Here is the full list of all 10 Nandemoya of Flower Street achievements.
Complete Chapter 2
Complete all entrustments of Mizuho
Complete all entrustments of Kaede
Complete all entrustments of Kasumi
Complete Chapter 9 - 5 on hard mode
Obtain all equipment
Obtain all skills
Obtain all amulets
Complete 100 entrustments
Complete Chapter 10 - 5 on hard mode