Arabica

Main character encounters a woman falling off the window and getting hospitalized as a result. In order to help her he agrees to start a part time job in her coffee shop. However, it turns out to be a maid cafe with triplets as waitresses! The look and sound absolutely alike, so protagonist can never guess who he's talking to. But girls personalities are different - one likes to make fun of protagonist, the other one is a free spirit while third one shows almost motherly love.

[From vndbreview]