Kaette Kita Jikou Keisatsu

One year has passed, Kiriyama works at the same police station, and he is still interested in unsolved cases which belong to the statute of limitations. Together with his assistant Mizazuki (who is actually in love with Kiriyama), Kiriyama solves those cases as his hobby. He still gives the "I won't tell anyone" card to the culprits.
(Source: Sukachu at MDL)