Tenisu no boifurendo Lyrics

Lyric discussion by Miss Wilde 

Cover art for Tenisu no boifurendo lyrics by Freezepop

I guess it's about a girl who has a crush on a guy who plays tennis. shrugs

xxgonexx, I'm still learning Japanese so I can't translate the whole thing, but heya means room. House is ie (and home is uchi). So the second-to-last stanza says,

But today it's raining So (because of that) I'm in your home You are very cute I want to go to your room

I think the boy is teaching her how to play tennis and when it starts raining they go inside. It's kind of a sweet song :)