All locations:
School Entranceway - behind the second lamp post on the right.
School Building 1F (1) - Straight past the entrance, between two pillars with red and blue decorations on them.
School Building 1F (2) - At the end of the faculty office hall, near the printing room.
School Building 2F - In a sink near the stairs that go to 3F.
School Corridor - on the other side of the persimmon tree, on a bench.
Gym Hallway - near a locker on your left.
Iwatodai Station - next to a cone near the closed off manhole.
Strip Mall 3F - Near the right side stairs.
Naganaki Shrine (1) - very top left, near the torii/shrine gate where you can duplicate skill cards.
Naganaki Shrine (2) - bottom left, near the jungle gym.
Port Island Station - near the cinema, on a red bench.
Station Outskirts - in front of the trash bags at the end of the area.
Dorm 4F - near the lamp next to the stairs that go to 5F
Paulownia Mall - Straight ahead, right below the fountain.
Dorm Rooftop (available 5/25 or later) - in the corner left of the plants.
Club Escapade (requires rank 2 courage) - right in front of the stage.
All fragments can be obtained immediately on 4/21 except for the rooftop and Club Escapade ones.