Hi o/

This will be my second guide and I'm writting while playing this game for the first time. English is not my native language, so I appreciate for kind corrections in the commentaries.

Most achievements will be unlocked naturally while you play the game until the very end of the post-game and there is only one missable so far as I know, even the achievements to marry specific characters can be achieved in the same save with the Rewoven Fate mechanic .

Update: I got a job, yay me! It slowed down how much time I can spend playing, so I'll come back in the weekends.

Update: My job is really eating my time, I don't have a date when I will come back to this guide, sorry.

Important things I'll add while playing.

• Don't go to sleep without fully using your Rune Points (RP) with your sacred tools. This will give you XP to spend upgrading your Sacred Skill Trees.
  
• There's one missable achievement because of a main story decision, without spoilers, always try to save everyone. regardless of the price you need to pay. My Advice? Money.
  
• Early game, put your villagers to gather lumber and stone. After you find that you have enough of both materials, you can return them to farming. But even then, first time at the morning go use Drum Dance in your farms and collect the crops yourself to receive a fair amount of All-Purpose XP.
  
• The Sacred Treasures you receive can also act as weapons that spend rune points and is one of the most efficient ways to beat bosses by using the treasure that target its elemental weakness.
  
• The best source of All-Purpose XP is harvesting your fields in all four villages every morning. can get around 250 XP per day on average.

Achievements from the Quests in-game section. Those are not missable because those are integrated in the main quest and you neeed to complete them to progress the game.

Clash of Dragons

It's over Subaru/Kaguya! I have the cooler Dragon!

The Spring God's Dream Visit

Love at first sight is not a lie.

Ulalaka Return

Yes.

A Village Reborn

Upgrade the Village level for the first time.

Cooking 101

Cook for the first time.

Defeating Mezuki

¡Olé!

Defeating the Cursed Tree

Stop bombing yourself!

The White Dragon's Transformation

This got me by surprise how early it was. Thought woolby claiming to be a dragon would be a running joke.

The Summer God's Dream Visit

Agree with you Sis, a Sword should be well maintained.

Matsuri's Entrance

Ah! The meathead... I mean! The Firecracker is here!

The Autumn God's Dream Visit

Come on! A festival is cool!

Kurama The Great Storm Tengu

Prideful he is.

The Winter God Dream Visit
Oh, God hunting! A totally normal hobby of Azuma.

Winter Wolf Fubuki
Eh, I have seen imoto-type characters, but this is the first time I see a character with ototo vibes.

A Fated Reunion

The Rival appears!

The First Meeting of the Gods

I want a Dango.

Astral Shrine 1

Flashback.

Astral Shrine 2

Another Flashback.

Astral Shrine 3

And yet another flashback.

Astral Shrine 4

Answers. And more questions.

Second Meeting of the Gods

Two missing gods.

The Oni God Restored

The truth! Yachiyo-san is the true Oni God! At least for me.

The Third Meeting of the Gods

There is a missing case? There is always only one truth!

A Moonlit Party

Aka The Fourth Meeting of the Gods.

Divine Severance and Ritual of Sacrifice

Final battle against the Black Rider! Marriage system unlocked! Absolutely save who needs to be saved for you not to miss a achievement!

A Prayer for the Future

Thanks Iroha.

Hostilities with the Hound

You...!

Infiltrating the Tagesanbruch

I'm a Ninja now.

The Fifth Meeting of the Gods

Resolution for battle!

A New Power

Oh yeah, training arc!

A Castle in the Sky

The final rush.

Dance of the Sovereign

I'll be the hero I need to be! End of the Main Story.

I made a separated section to streamline the Guide. Those achievements follow the Main Story of the game but there is a clear "breakpoint" to access those quests. You need to marry one of the bachelor/bachelorettes and have a child. None of those re missable.

The Fruit of our Love

Sniff... Man, childs are the treasure of humanity.

The Sixth Meeting of the Gods

Consequences after spliting heaven and hell.

The Seventh Meeting of the Gods

Resolution for the final journey.

Divine Glory Forevermore

A important choice. I honestly think this decision should be related by who is your wife/husband and not the protagonist itself. This hit specially deep because I married Ulalaka and her questline showed some of her fears, and the choice here is really related to her fears.

Achievements related to Battle Mechanics.

It's Better with Friends

Add a character to your party. To add a character to your party, you need at least bond level 1 with them.

Achievements relateds to characters, the "true NPCs" which you can achieve bond levels. There is one missable achievement related to a choice in the main story related to your rival, the Black Rider.

You can get all marriage achievements using Rewoven Fate mechanic. Basically Rewoving your fate allow you to enter in a parallel universe which all marriage candidates intimacy levels fall to the maximum of four hearts (bond level remain the same) and all other aspects remain the same.

Disclaimer: The use of waifu in this guide is totally my bias. You yourself should know who is your Waifu/Husbando. But being honest here... Ulalaka marriage is currently the most popular candidate in the achivement list here on steam xD

Cooking Together

Achieving bond level 6 with a character unlock the cooking together feature with specific recipes for each character, this activity also reward bond points. For Ulalaka for example, you can cook Egg Rolls with her.

My Marriage to Ulalaka

Best waifu.

My Marriage to Clarice

Second best waifu.

Achievements related to the Village Management system of the game. Not missable.

The Village Problem Solver

The Ema Board is basically a quest board with quests introducing new mechanics unlocked recently and miscellaneous quests that reward gold or building materials as stone/wood/soil.

The Village Counselor

Finish a Request quest from a true npc (those which you can achieve bond levels). In a certain point you can start to request those npcs if they need anything and they gives you a task.

A prosperous Village

Probably unlocked in your first or second night, basically go to sleep with positive gold income. You can see your profit of the day in the shipping bin any moment.

The Hidden power of Equipment

Upgrade a equipment for the first time. Basically you can upgrade old items to use them instead of crafting a new weapon, or at least until you find the recipe for a new weapon. But the upgrades are really, really expensive. The max level for a equipment is 9.

Achievements related to the Sacred Treasures and its abilities. You get those from the main quest. Not really possible to miss them.

Purification

As a Earth Dancer, go purify the world!

Drum Dance

First Sacred Treasure. Use it for the first time.

Sword Dance

Second Sacred Treasure. Use it for the first time.

Fan Dance

Third Sacred Treasure. Use it for the first time.

Parasol Dance

Fourth Sacred Treasure. Use it for the first time.

Mask Dance

Fifth Sacred Treasure. Use it for the first time.

Staff Dance

Sixth Sacred Treasure. Use it for the first time.

Contests are events you can schedule once per week. I would recommend scheduling it as soon as you unlock this because you will need at least 2 in-game months to play every single contest, for the achievements you need to end in first place at each contest. The event also give bond points for NPCs, helping to get the Bond Achievements. My advice is to start off with the Fishing contests, those are the easiest to win.

Freshwater Fishing Frenzy

This contest happens in Winter Village. You win by catching the most fish. Around 18 fishs are enough to win by a large margin, but only if you don't go to the shrine and rest until 7pm. If you do that the NPCs will fish like crazy offscreen and get like 24~26 fishs while you are sleeping, in this case you need to fish around 28. If you participate in the event without skipping time, they catch only 14~15 fishs.

Saltwater Fish Contest

The contest happens in Summer Village. Catch a Tuna. Seriously. It's probably the biggest fish in the Summer Village. You can even catch a Tuna and go sleep until 7pm that you still win. I don't believe NPCs can catch a Tuna like the player.

Pond Smelt Catch Contest

The contest happens in Winter Village. You need to catch many time a specific fish. Fishing around 10 of them is enough to win.

Squid Catch Contest

The contest happens in Autumn Village. You need to catch a Squid, the bigger the better. Like user Melodyhina123 commented, teleporting to Summer Village after this contest start, its seems relatively easy to get a squid with 42~45cm and the NPCs apparently only catch squids around 32~39. So I believe its safe to sleep until 7pm if you catch a squid with 42cm+