Kaiketsu Nikki

Nikki, the hero of the game, is a cybernetically enhanced young man from the future. His "home time" is the beginning of 22th century; his home town is the international megalopolis Shinjuku City, part of the old Tokyo. Humanity prospers, living in pleasure, relying on incredible scientific achievements. One of them is the time machine. Nikki finds out than four young, attractive school girls from 1994 got involved into some sort of trouble. Using his time machine, Nikki ventures into the past, determined to save them... and expecting a lot of... err... gratitude in return!

[From Moby Games]