Here is the full list of all 50 Love Tavern achievements.
Complete 4 chapters of Natsumi
Complete 4 chapters of Lilith
Complete 4 chapters of Emily
Complete 4 chapters of Toyo
Leona's story
Complete 4 chapters of Miwa
Learned 20 cooking recipes
Complete 4 chapters of Tamiko
Hire 10 five-star staff members
Complete 4 chapters of Flann
Complete 4 chapters of Nozomi
Hire 30 staff members
Cook 600 dishes
Welcome Natsumi to the tavern
Hire all unique staffs to the tavern
Collect 1000 ingredients
Welcome Toyo to the tavern
Cook 120 perfect dishes
Complete dungeons 50 times
Welcome Nadia to the tavern
Complete 4 chapters of Izumi
Served 1500 customers
Collect 1mil Gold
Clean 100 times
Welcome Emily to the tavern
Hire 1 five-star staff member
Welcome Lilith to the tavern
Provide 100 onsen services
Welcome Flann to the tavern
Provide 100 massage services
Provide 100 sauna services
Build a single onsen room
Welcome Slyvia to the tavern
Welcome Sakura to the tavern
Build a single cleaning room
Welcome Miwa to the tavern
Welcome Tamiko to the tavern
Welcome Nozomi to the tavern
Build a single sauna room
Build a massage room
Build a single storage room
Welcome Leona to the tavern
Build a single hunting room
Earn 7777 gold
Build a single dining room
Build 40 of any type of room
Welcome Izumi to the tavern
Hire a staff member
Build a single dormitory
Build a shop