うれしい、しあわせ In Kanji, 嬉しい、幸せ eg: I'm happy to hear that. (それを きいて 嬉しい です。) I'm happy to be married you. (あなたと けっこんして 幸せ です。)

I believe it's うれしい

By the way, you can also say ハッピー. If you don't know how to say something in Japanese and are just too lazy or tired to consult a dictionary, you just make the English word sound Japanese. There is a large chance that people are gonna understand you. It's an expedient tactic I want to share with you. Hehe :)