So, I live in sharehouse in Japan. There was some dude there who I wasn't in a very good relationship with because he is a beta and envies me that I get girls etc. I know he doesnt like me. He moved to other sharehouse like 3 or 4 months ago. Today I saw him in my sharehouse. I know that our sharehouse will be over soon so he cannot move in here(sharehouse will be over in 1 month). So probably he visited just for memories or something. Nevermind. Anyway, I put my clothes in common washing mashine, when I come back to take the clothes they kind of dirty. Probably this guy threw some rubbish in the washing mashine. There was a rubbish box near washing mashines and when I looked in it it was empty. So I see this guy in the lounge room, go to him and tell him:"I just took my clothes from the washing mashine and saw they are dirty. Is that you who did that?" Ofcourse he said no. I said: if something like this happens again I wont talk anymore and punch you in the face. He said ok. So now Im concerned. This guy will probably not come to this place anymore. This place will be over soon. But what should I do in that situation? This guy is pathetic beta he plays videogames all the time. And what should I do if somehow this situation happens next time? I cannot fight here because there are strict police laws in this place and fighting is strictly prohibited. If I punch him in the face I will probably be departed from the country(I live in Japan). Any advice please? Also, sorry for my bad English, Im not a native speaker.