During the investigation, you must gather clues about the murder by interviewing other students and examining objects. As the investigation progresses, you will obtain Truth Bullets—hints that will help you solve the case. These hints may range from physical evidence to students detailing their account of events.
Furthermore, there are hidden Monokumas lurking throughout the island. If you can find them, you will earn a huge Monocoin payday.

During Free Time, you can choose a student to spend time with and get to know them better. By spending time with a student and giving them presents, you can learn their personal secrets and form a stronger bond with them.
Presents can be obtaining either through the Monomono Yachine or vending machines.

You can use these machines once you’ve reached a certain point in the story. By spending Monocoins, you can obtain various presents.
The Monomono Yachine dispenses different presents at random, while the vending machine allows you to spend set amounts of Monocoins to obtain specific presents.