Here is the full list of all 21 Umichan Two Scoops achievements.
Beat the game without Maiko and Pattie participating in any adult situations
Complete Tsugo's ice cream.
Turn off the screen lock in the settings.
Watch the animation in the intro scene for 10 seconds or longer
Watch any replay.
Get more than 24 Money.
View the Leo scene.
Complete Leyah's ice cream.
Complete Joey's ice cream.
Complete Savori and Amber's ice cream.
View the Joiry scene.
Get cherries
view Percival scene
View Pattie throwing ice cream at David
Get strawberries
View Chris scene with Peach and Creamy
Have a wardrobe malfunction
View the David scene
Make first ice cream successfully.
View Maiko and Pattie's selfie images.
View the in game comic.