Yeah yeah singing challenge's Things

so basically i was playing a game (roblox, if u must know) and i was in a server with someone who claimed to Japanese, but i was a bit fishy about it. heres why: their profile before was english and it was pretty good, but they acted like their english was bad. and later on, their profile was in Japanese, instead of english.

so i confronted them and they said they used a translator, which kinda made me question, why would they do that in the first place??

also bc one person typed a nice but quite long sentence and the person who claimed to be Japanese put ":D" but they said they knew little english, so how could they read that so fast?

the last thing was the way they typed in Japanese. i am not Japanese, nor am i fluent in it, so when they spoke in Japanese, i did not know what they were talking about. so im pretty sure u can write Japanese in different ways right? one way is like the english alphabet and the other is characters (pls any Japanese or Japanese speakers, correct me if im wrong) But they switched between those two which made it kinda fishy. why couldnt they just stick to one?

so this is where i need help. to anybody who may be japanese or speaks the language, is that normal or fishy? again, im not japanese or speak it so i have no idea. should i mind my own business or confront them bc i know there are ppl who fetishize, if thats the right word, other cultures and stuff, so im a little paranoid, u can say.

they also play this game quite a lot bc they joined the server i was in about 2 times, so if u wanna see for urself, just tell me and ill tell u what its called.

anyways, srry thats its so long, i was just wondering. and have a good day/night!!