This is my first guide so if I need to make any adjustments or add screenshots, please let me know. This guide will have some spoilers so beware of that. Also note that money, items, skills, and level do NOT transfer over in NG+ so keep that in mind when going for certain achievements.

• Dark Realm Wunderkind - Win your first battle.
  
• Demon Charmer – Gain a demon ally through the art of confinement.
  
• I am Raidou Kuzunoha XIV – Succeed the name of Raidou Kuzunoha.
  
• Rising Devil Summoner – Enter the Dark Realm for the first time.
  
• Episode 1 Complete – Reach the end of Episode 1.
  
• Episode 2 Complete – Reach the end of Episode 2.
  
• Episode 3 Complete – Reach the end of Episode 3.
  
• Episode 4 Complete – Reach the end of Episode 4.
  
• Episode 5 Complete – Reach the end of Episode 5.
  
• Episode 6 Complete – Reach the end of Episode 6.
  
• Episode 7 Complete – Reach the end of Episode 7.
  
• Episode 8 Complete – Reach the end of Episode 8.
  
• Episode 9 Complete – Reach the end of Episode 9.
  
• Episode 10 Complete – Reach the end of Episode 10.
  
• Episode 11 Complete – Reach the end of Episode 11.
  
• Final Episode Complete – Reach the end of the Final Episode.

• Shrewd Opportunist – Have Gouto pay the streetcar fare.
  You need to ride the streetcar without having the money to pay for it. You can spend it all at Konnou-ya and then ride the streetcar. He will take the money you owe him once you have the sufficient funds. It is easiest to do this towards the beginning of your playthrough before you get a large amount of money.
  This achievement is missable if you complete Case File No. 36 (HERE, FOR YOU) as the reward is a Streetcar Pass and gives you free rides.
  
• Timeless Summoner – Forge all weapons. (See Sword Alchemy section)

• Capital Defender – Perform demon fusion for the first time.
  You’ll get this naturally; just perform a fusion at Goumaden.
  
• Gifted Youth – Revive from death.
  Once you die in battle, choose the option to retry the battle and the achievement will pop.
  
• Taisho Swordsman - Complete a case file. (See Case Files section)
  
• Lightning Blade - Complete all case files. (See Case Files section)
  
• Local Hero - Purge an Aril Rift. (See Aril Rifts Section)
  
• Vanquisher of Evil - Purge 20 different Aril Rifts. (See Aril Rifts Section)
  
• Master of Demons – Perform Raidou’s Combat Skills 300 times.
  You’ll likely get this naturally. The first set of combat skills are given to you (Pyro Sign, Frost Sign, Volt Sign, Wind Sign) and the rest are gained through Sword Alchemy.
  
• Peerless Champion – Defeat 1,000 enemies.
  
• Hand of God – Perform Sword Alchemy for the first time. (See Sword Alchemy section)
  
• Legendary Kuzunoha – Defeat enemies with Devil’s Bane 50 times.
  Devil’s Bane can be performed after you’ve knocked the enemy off balance with a continuous assault or evaded an attack with perfect timing. To get the achievement, you have to deal the final blow with Devil’s Bane. It may be easier to fight solo or make sure your demon allies cannot use skills so they don’t kill the enemy before you can use Devil’s Bane.
  
• Underworld Savant – Gain 30 demon allies through the art of confinement.
  This will likely happen naturally. Just confine every new demon you see throughout the story.
  
• Konnou-ya Habitué – Obtain the highest discount at Konnou-ya.
  The amount you spend at Konnou-ya will carry over through playthroughs so don’t worry too much if you don’t get it the first time around. Just spend money on supplies or materials until it pops.
  
• Renowned Summoner – Perform 50 demon fusions.
  If you are trying to fill out the Devils Chart, you should get this naturally.
  
• Demon Commander – Receive 50 letters from demon allies.
  When you raise a demon’s loyalty to max and then fuse them, they will leave a letter behind. If you fuse two that have their loyalty maxed, only one letter is left behind so only one demon needs to have max loyalty to get a letter.
  
• Demons’ Terror – Defeat the boss at the bottom level of the Training Hall.
  You need to defeat Beelzebub at level 10 of the Training Hall. You will need to complete the previous Training Hall case files to unlock it. The files you will need to complete are:
  - No. 27 Trial of a Hundred Demons Pt. 1 on level 5
  - No. 34 Trial of a Hundred Demons Pt. 2 on level 7
  - No. 39 Trial of a Hundred Demons Pt. 3 on level 9
  - No. 43 The Final Act on level 10.
  
• Prodigy – Leave a money offering at the old shrine.
  You can leave money at the old shrine in Dark Sakuradayama. Leaving any amount should pop the achievement.
  
• Urban Mystic – Become a recognized regular of Shin-Sekai.
  Like Konnou-ya, you just have to keep spending money until it pops. The last sodas added will be Harvest Pop and the Deus Pop.
  
• Silver-Tongued Devil – Gain Beelzebub as a demon ally.
  After defeating Beelzebub on level 10 of the Training Hall, he can be fused at Goumaden.
  
• Dimensional Detective – Learn all of Raidou’s Combat Skills.
  Combat Skills are gained through sword alchemy. The weapons you will need to fuse are:
  - Bizen-Osafune, Muramasa, Bakuya, and Kanshou from the Swords path.
  - Himezuru, Kogarasumaru, Plasma Sword, and Raikiri from the Spears path.
  - Type 32 Gunto, Kiyotsune, Doujigiri, and Seimitsu from the Axes path.
  
• Valiant Hero – Gain Raiho as a demon ally.
  Can only be complete in NG+. In Episode 1, the case file No. 45 A New Hero Emerges will unlock after you get the wine from the servant. You will need the Master of Demons title, which unlocks after you gain 5,900 loyalty points. Once you have it, talk to Detective Kazama by the bridge and he will give you the Bancho Uniform. After receiving it, go outside Konnou-ya and choose to fight Raiho after the cutscene. Once you do, Raiho will be available to fuse at Goumaden.
  
• Worldly Summoner – Raise your Summoner rank 30 times.
  You will need 25,000 loyalty points to unlock this achievement. You can check your Total Loyalty under Configuration and choosing Raidou's status; it will be under the EXP bar. Loyalty is carried over so this can be completed in NG+ as well. The easiest way to grind this is to fill your tubes with low-level demons that don’t have their loyalty maxed out and do instant-win encounters in the Village Halls or the Training Hall. Once they max out, release them and resummon them, then repeat.
  If you registered all your low-level demons in the Devil Chart with max loyalty, fuse new versions of them then register those in the Premium Devil Chart so you don’t have to keep fusing them.
  
• Unbound Summoner – Register all demons in the Devil Chart. (See Devil Chart section)
  
• Sovereign Summoner – Complete the game on Detective Legend difficulty.
  This achievement only requires you to complete the final boss battle on Detective Legend difficulty. You can do the rest of the playthrough on a lower difficulty if you wish, and just switch difficulties before the boss battle.

• Local Hero – Purge an Aril Rift.
  
• Vanquisher of Evil – Purge 20 different Aril Rifts.

None of the Aril Rifts are missable and only repeatable rifts count, so the ones that you will encounter during Case Files (not No. 1) that disappear do not count. You can easily see these on the map after you complete Case File No. 1, they are the red rift symbols surrounded by a yellow square. More will be added as you progress through the story.

• Tsukudo-cho – 3 rifts
  
• Daidouji Residence – 2 rifts
  
• Ginza-cho – 3 rifts
  
• Fukagawa-cho – 2 rifts
  
• Red Light District – 1 rift
  
• Daidouji Textiles – 1 rift
  
• Harumi-cho – 3 rifts
  
• Kasumidai – 3 rifts
  
• Sakuradayama – 2 rifts

• Taisho Swordsman – Complete a case file.
  
• Lightning Blade – Complete all case files.

There are 45 Case Files, but one of them will need to be completed in NG+. If you do all the Case Files in your first playthrough, you just need to do the last one in NG+ to unlock the achievement. It’s up to you whether you want to do all of them again in your second playthrough. They are not missable and you can complete them in any episode other than 9 due to plot reasons. The Case Files are pretty self-explanatory as they tell you exactly what you need to do.

• Hand of God – Perform Sword Alchemy for the first time.
  
• Timeless Summoner – Forge all weapons. *MISSABLE*
  Make sure you don’t sell your weapons as most are needed to forge others.

If you do not have the Village Training DLC, then you should grind for money in the final level of the Training Hall. There are 46 weapons but 4 of them can only be gained in NG+. Like the Case Files, you can do the initial 42 weapons in your first playthrough, then the last 4 in your second and still get the achievement. It’s up to you if you want to fuse them all again in your second playthrough to get Combat and Sword Skills. If you only fuse some in your first playthrough, make sure to note down which ones as it won’t indicate in NG+ the ones you already fused (if you don’t want to do certain ones again if it’s not necessary).

• Swords (14)
  - Bizen-Osafune
  - Kotetsu
  - Muramasa
  - Usumidori
  - Bakuya
  - Masamune
  - Kanshou
  - Kusanagi
  - Kurikara
  - Murakumo
  - Onigiri
  - Kikouseiken
  - Kagutsuchi

• Spears (14)
  - Himezuru
  - Kanesada
  - Kogarasumaru
  - Kogitsune Kage
  - Plasma Sword
  - Luna Blade
  - Trishula
  - Tsukikage
  - Kogitsune
  - Raikiri
  - Gae Bolg
  - Sol Blade
  - Futsu Mitama
  - Longinus

• Axes (14)
  - Type 32 Gunto
  - Nagamitsu
  - Kiyotsune
  - Nagamichi
  - Doujigiri
  - Ameno-Ohabari
  - Totsuka
  - Mitsurugi
  - Shishiou
  - Seimitsu
  - Balmung
  - Vanargand
  - Mjolnir
  - Youkou Haken

• Special, NG+ (4)
  - Shichishitou
  - Tentei Sword
  - Laevateinn
  - Ameno-Nuboko

Note that some materials are missable.

• Pyro Bronze/Steel/Gold – Defeating the respective Order and Konnou-ya.
  
• Frost Bronze/Steel/Gold – Defeating the respective Order and Konnou-ya.
  
• Pagan Bronze/Steel/Gold – Defeating the respective Order and Konnou-ya.
  
• Wind Bronze/Steel/Gold - Defeating the respective Order and Konnou-ya.
  
• Skill Bronze/Steel/Gold - Defeating the respective Order and Konnou-ya.
  
• Fury Bronze/Steel/Gold - Defeating the respective Order and Konnou-ya.
  
• Volt Bronze/Steel/Gold - Defeating the respective Order and Konnou-ya.
  
• Renki
  - Case Files No, 7, No. 15, No. 18, No. 24, No. 29, No. 45.
  - Defeating Chernobog in Episode 3.
  
• Moon Chip
  - Amazing Science Lab, a demon with the Inspect ability is needed.
  - Defeating Mishaguji in Episode 8.
  - Defeating the story boss in Episode 9.
  - In Shipyard B3, behind the Bullet Nethergate you’ll go through during the story. *MISSABLE*
  - Training Hall B7 in a destroyable object.
  - Training Hall B8 in a destroyable object.
  
• Plastic
  - Case File No. 23
  - In Kasumidai near the Supreme Court, a demon with the Sneak ability is needed.
  - Defeating Nebiros in Episode 5.
  - In Shipyard next to the Ippon you need to speak to during the story, in a destroyable object. *MISSABLE*
  - In the Akarana Corridor 1950, a demon with the Inspect ability is needed.
  
• Onogoro Ore – Training Hall B3 in a destroyable object.
  
• Element #115
  - Defeating Abihiko and Nagasunehiko during Episode 5.
  - In Sakuradayama by the statue near the entrance, a demon with the Inspect ability is needed.
  - In Sakuradayama north of the shrine, in a destroyable object.
  - In Shipyard B2 in a destroyable object. On the top level, go all the way to the right then jump down. When prompted, jump to the right side. *MISSABLE*
  - Defeating Sukuna-Hikono during Episode 10.
  - Training Hall B9 in a destroyable object.
  
• Strife Blade – Case File No. 23
  
• Hunger Scale – In Waden One (Upper) with the differing paths in a destroyable object. *MISSABLE*
  
• Pentagram – In Shipyard B4 past the Moon Chip, go down the stairs to the right, in a destroyable object.
  
• Aletia – Training Hall B10 in a destroyable object.
  
• Mirror of Sun – Case File No. 43 The Final Act
  
• Homusubi Crystal – In the Akarana Corrider 1950, use the portal to the right of the portal needed to progress the story. A demon with the Inspect ability is needed.
  
• Shadow Magatama – In the Akarana Corridor 1960, on the left side behind the time tourist, there is a crack in the floor. A demon with the Inspect ability is needed.
  
• Light Steel – In the Akarana Corridor 1990, there will be a barrier in the bottom part of the area. Use a demon with the Inspect ability to go through the barrier and pick up the item.
  
• Mortal Seal – In the Akarana Corridor 2050. When in the year 2020, go to the portal past Mada and send a demon through the portal to obtain the Seal.
  
• Victory Crown – In the Akarana Corridor 1990. After progressing the story and unlocking the portal to the final boss, go back to the portal at the end of the area in 2020. There will be a puzzle in 20XX where you will need to send demons out on a solo investigation:
  - Frost to the left
  - Volt to the left
  - Fury to the right
  - Pagan to the right
  After going through the portal, send your demon through the next purple one.
  
• Sessho-Seki – After doing the puzzle in 20XX, the same purple portal that is used to obtain the Victory Crown is also used to obtain this item. This time, send a demon with the sneak ability out Solo and it should take them to a different area in 2020.

• Unbound Summoner – Register all demons in the Devil Chart.

To complete the Devils Chart, you will need to fuse five versions of Legion, which is only gained through a fusion accident. Fusion accidents occur during the new and full moon phases, and increase with a higher luck stat. If you have the Kuzunoha Village Training DLC, you can grind luck incenses in the Indulgences Hall. If not, it might be easiest to do this at the end of your first playthrough as you’ll gain some incenses naturally through the story.

I did this during my second playthrough and I don’t know if this part actually has any effect on the Legion fusions, but I could only get them to fuse after Chapter 3 or 4. When you fuse one, keep it in your tubes as it will prevent that same version from fusing again. You can get four or so lower-level demons with max loyalty to fuse and save scum until you get all the versions you need. If you stop getting Legion accidents, try going to the next phase and continue the process. This worked for me after fusing three of them, then going to the next phase to fuse the last two.

The five versions of Legion will each have their own chart entry. They are all in the Skill order and are simply listed as Legion, here are the different versions:

• Legion (1)
  

• Legion (2)
  

• Legion (3)
  

• Legion (4)
  

• Legion (5)
  

Most unregistered demons are easy to search for through search fusion, select Show only unregistered demons and Include demons in Devil Chart for fusions. If the result is too big you can filter it down a bit more by Order and Level.

Some demons will only unlock for fusion by completing certain Case Files:

• Beelzebub – Case File No. 43 The Final Act
  
• Kudan – Case File No. 29 Enter Kudan
  
• Belphegor – Case File No. 40 Scars of the Recession
  
• Asura – Case File No. 44 A Transcendent God
  
• Raiho – Case File No. 45 A New Hero Emerges (NG+)
  
• Hayatoro – Case File No. 19 Enter Hayatoro
  
• Yoshitsune – Case File No. 23 Yoshitsune’s Test
  
• Alice – Case File No. 31 Hello…?
  
• Mot – Case File No. 35 The Prince of Darkness