Tsuukin Kairaku 2 Chikan de Go! Go! by Haoh - Adult Sex Game

Main character is an office worker who has to get to work by the second most popular train line among molesters.
One morning he gets in a packed train with his hand pressed against his colleague body. He withdraws his hand, but feels body sensation from the move. From that moment life of an ordinary salary-man starts to change.