When the protagonist walks Koromaru at night, either a dorm mate will go along and Koromaru will find an item, or the protagonist will encounter a Social Link and gain +15 Social Link points. Who appears on which date are all fixed.
Many new activities were added to the dorm in Persona 3 Reload including:
More social opportunities with dormmates
Watching movies on the DVD player in the lounge
Gardening on the dorm roof
Reading on the second floor
Cooking in the communal kitchen
Studying with dormmates in the dining room
Using the shared computer to improve Social Stats, Tartarus skills, secret vendor and vending machine items, and Social Link points
Fridge
On waning and waxing moon nights, there will be space in the fridge for the protagonist to leave Lukewarm Taiyaki for Request #38. By the next day, it will turn into Chilled Taiyaki. However, someone else in the dorm might take the taiyaki and leave other items in the fridge that the protagonist finds instead of the taiyaki. If 60 days has passed since the taiyaki was put into the fridge before the protagonist checks it again, then it will turn into an Odd Morsel instead.
Days when it is possible to leave Lukewarm Taiyaki in the fridge: 5/2, 5/31, 6/16, 6/30, 7/29, 8/27, 9/13, 9/26, 10/25, 11/11, 12/10, 12/23, 1/9 and 1/22.
The following chart lists what will be in the fridge when the protagonist tries to retrieve his taiyaki.
