Welcome nekoreichan.
I was in an almost identical situation to you. I was in love with a Japanese girl who came to England to study. However it was I who was the Witness.
She did not return my feelings at first and, like one of the posters related above, it was "okay" for me to pursue her without worrying too much--I couldn't have her. I worked tirelessly, pursued her in all the traditional ways: chocolates, flowers, poetry, tickets to the ballet (I even had her fitted for a dress and bought matching jewellery) and eventually she did return my feelings and we even planned to marry.
This put me in a difficult position but she had been studying with me (as a JW) for quite some time by then, and so I was hopeful that she would eventually get baptised. However, she eventually told me that she could not accept the religion. This led to all sorts of problems. I planned to marry her whether she converted or not as I loved her so much, but I just could not stop seem to stop myself from badgering her and trying to convert her (I was trying to save her life after all..."sigh"). This eventually tired her and the battle of wills eventually made us both ill. Soon after, her parents got wind of the whole thing. First objection: I was a "gaijin" (foreigner). Second objection: I was a Jehovah's Witness and her mother knew all about the religion. As you can imagine, it all ended badly: we both said and did a lot of hurtful things. I am ashamed of myself but I tell you this: it was my manipulative and controlling attempts to make her submit to the Watch Tower which were most toxic to our relationship. She said I was like two people: a kind, romantic and gentle man who put her first, most of the time; but an unreasonable tyrant when it came to religion.
This is my point nekoreichan: he may love you and he may even get the courage to court you, but he will not be able to stop himself from trying to manipulate and control you as long as he is indoctrinated. He believes that you will die a painful and agonizing death if he does not convert you and this will haunt him until he can get you into the Watch Tower. I know this because I was him six years ago. You have got some good advice from other posters and I would like to echo some of the advice they have given you. Perhaps you can help him awaken? That is your choice but be careful. Others have explained the choices you have. I would give their comments due consideration.
Kindest regards,
Tea drinker