We require the voice actor to know English or Japanese, we could do a test to see if his acting and voice fit.
Since this game is free they must do it because they want to do it for free. In this game we only spent our time, it costs nothing to produce only our time.
Ok... I'm no expert voice actor, but if time passes by and you find no one qualified, then I could try to dubb one of the boys' voices from the tickle lab
