Once Odd Eye touches a person, his Quirk will force them to expose things they don't want others to know or embarrassing things about their past that they want to hide.
Odd Eye has to touch the victim in order for the Quirk to work.
With willpower, the victim can avoid speaking openly about their secrets, although in this case Odd Eye himself is the one who will reveal them, although less precisely. With enough willpower, the Quirk may not work, even if the secret is truly shameful.
- My Hero Academia: Team-Up Missions Manga: Chapter 4.