This is my simple guide for finding the hidden achievements in Holodori.
I made this guide for players who have already found some hidden achievements by themselves but are having trouble discovering the rest. I’ll explain where I need to go, what I need to do, and any extra steps needed to unlock each achievement.
Harmony Garden (HG) Hidden Achievements
If I missed anything or if something needs correcting, please feel free to leave feedback or suggestions.
Note: Some achievements require me to unlock certain areas, buildings, or upgrades before I can complete them.
[HG1] 1000 Knocks of Pain
To unlock 1000 Knocks of Pain, I need to knock on the door behind the Gamers Station reception desk three times.
Type: Instant
How I unlock it: I go behind the Gamers Station reception desk and knock on the door three times. After that, an animation plays where the holomem inside walks to the door and knocks back at me, which unlocks the achievement.

[HG2] Photosynthesis
For Photosynthesis, I sit on the bench in front of holo Home.
Type: Instant
How I unlock it: I sit on the bench in front of holo Home. If the achievement does not unlock immediately, I try changing my sitting position until it triggers.

[HG3] Comfy
To earn Comfy, I simply sit on the sofa inside holo Home.
Type: Instant
How I unlock it: I enter holo Home and sit on the sofa or one of the blue chairs inside. The achievement should unlock after sitting down.

[HG4] Movie Night
Here, I need to sit at HOLO Cinemas and enjoy some popcorn to unlock Movie Night.
Type: Instant
How I unlock it: I go to HOLO Cinemas and choose one of the front seats. An animation starts where my holomem eats popcorn, and the achievement unlocks.

[HG5] Treasure Hunt
For Treasure Hunt, I check the wooden box beside the h3ro vehicle.
Type: RNG
How I unlock it: I go to the right side of the h3ro vehicle and interact with the wooden box containing maps. This achievement is random, so I may need to try several times.
When it works, my holomem performs a celebration jump, which confirms that I unlocked it.

[HG6] I hate customers like you
To unlock I hate customers like you, I need to knock on the door behind the Wheel of Kiseki reception desk three times.
Type: Instant
How I unlock it: I go behind the Wheel of Kiseki reception desk and knock on the door three times. Just like the Gamers Station achievement, an animation plays where the holomem inside knocks back at me.

[HG7] I Hate Mondays
This achievement requires me to hit the pipe at the Cho-Very-Ba Drepa Branch Station and create a large cloud of smoke.
Type: RNG
How I unlock it: I find the interactable pipe on the side of the building and keep trying until the animation triggers. When all the pipes release steam, the achievement unlocks.

[HG8] Breakfast anyone?
All I have to do is take a piece of toast from the toaster at Toko Holoro.
Type: Instant
How I unlock it: I walk up to the toaster in Toko Holoro and interact with it once. Taking out the toast unlocks the achievement.

[HG9] Aaaand I’ve Done It
This time, I need to take out a burnt piece of toast from the toaster at Toko Holoro.
Type: RNG
How I unlock it: I repeat the toaster interaction from the previous achievement until I eventually get a burnt piece of toast. This one is random, so I may need a few attempts.

[HG10] Can’t Fight the Pull
To unlock Can’t Fight the Pull, I shake the trees near Tarafuku Journey until apples fall.
Type: Instant
How I unlock it: I go to the tree on the left side of Tarafuku Journey and shake it. Once the animation plays and apples fall down, I unlock the achievement.

[HG11] What’s For Dinner?
For What’s For Dinner?, I take a seat on any stool inside Tarafuku Journey.
Type: Instant
How I unlock it: I enter Tarafuku Journey and sit on any stool inside. The achievement unlocks automatically.

[HG12] Aiming even higher
My goal is to reach the top of Face Mountain and perform yoga to unlock Aiming even higher.
Type: Instant
How I unlock it: I climb to the top of Face Mountain and perform the yoga pose while standing on one of the heads. I only need to use one head to unlock this achievement.

Mega Sphere (MS) Hidden Achievements
These are all of the hidden achievements I can unlock in Mega Sphere. Some of them are easy to get, while others require me to win a game or get lucky.
[MS1] Hajime no Yubi
To unlock Hajime no Yubi, I need to win a match at the Shibakiage Fighting game.
Type: RNG
How I unlock it: I go to the Game Area and sit at any of the Koronesuki fighting game consoles. I let my holomem play, and once I win the fight, the victory screen appears and unlocks the achievement.
This achievement requires a win, so I may need to try multiple times.

[MS2] Dance Floor Fairy
Play 1 game at the Dance Dance Phoenix.
Type: Instant
How I unlock it: I go to the Game Area and find the KFP Dance machine. I interact with it once, and the achievement unlocks immediately.

[MS3] Crane Magician
Here, I play a round using one of the Robo-Robo Crane machines.
Type: Instant
How I unlock it: I go to the Game Area and interact with any crane game machine. I do not need to win; simply playing the game is enough to unlock the achievement.

[MS4] Top Pilot
To earn Top Pilot, I play one game on any Onigiri Panic machine.
Type: Instant
How I unlock it: I find any Onigiri Panic machine in the Game Area and interact with it once. I get the achievement even if I do not win the game.

[MS5] Finish Them!
For Finish Them!, I complete one game at the Pekorumble Derby.
Type: Instant
How I unlock it: I go to the casino floor and find the giant Nousagi. I interact with it and watch the animation until it finishes. After that, the achievement unlocks.

[MS6] Now, this is card gaming!
This achievement requires me to win a card game at the MoonAce table.
Type: RNG
How I unlock it: I go to the casino floor and find the blackjack table between the slot machines and the Raven Bar.
I sit on the middle stool and watch the dealer give me three cards. I need to win the game before the achievement unlocks, so I may need a few attempts.

[MS7] This is from that customer over there.
All I have to do is order a beverage from the Raven Bar.
Type: Instant
How I unlock it: I go to the casino floor and find the Raven Bar, which is located between the giant Nousagi and the slot machines.
I sit on the middle stool next to the bartender and watch the animation. Once it finishes, the achievement unlocks.

[MS8] Zawa Zawa
To unlock Zawa Zawa, I need to hit the Mega Slot jackpot by getting three lucky 7s.
Type: RNG
How I unlock it: I go to the casino floor and find the Mega Slot machines on the left side of the entrance.
I choose any slot machine and keep playing until I get three lucky 7s. This achievement is random, so I may need many attempts before I hit the jackpot.

Final Notes
That covers all of the hidden achievements I found in Harmony Garden and Mega Sphere.
Some achievements are instant and only require me to interact with an object, while others depend on luck or winning a mini-game. If an achievement does not unlock right away, I usually try again because some of them have random triggers.
Good luck finding all the hidden achievements!