1: He is happy (as you already know) but so happy that he can even make Mr. Grumpy smile.
2: Mr. Grumpy and Mr. Miserable are his best friends; he always makes them smile.
3: He really likes the color yellowish because it matches his complexion and loves the smiley face asthetic.
4: Other friends include Mr. Tickle, Mr. Bump, Mr. Small, Little Miss Sunshine, Mr. Fussy, Little Miss Neat, Mr. Uppity, Mr. Strong, Mr Spiv, Mr Temper. Little Miss Bossy and others.
5: little miss sunshine it's your bestie And had a crush on her, she finds Little Miss Sunshine very cute and pretty, always ending with a kiss on the cheek.
6: He is a good, smiling guy, but sometimes he gets sad (even crying) either because nobody is happy or because Little Miss Sunshine is sad and crying a lot. He always comforts and consoles her with a hug. When it is Mr. Happy himself who is sad and crying, Little Miss Sunshine is the one who comforts and consoles him with a hug (but they don't just think about each other; they also think about everyone).
7: He also loves Playing, dancing happily (sometimes with Little Miss Sunshine), spinning, rolling, and jumping with Little Miss Sunshine, and also kissing Little Miss Sunshine and giving kisses to Little Miss Sunshine (which can be a normal kiss or a ticklish kiss), and also sleeping cuddled up with Little Miss Sunshine and also rubbing his nose with Little Miss Sunshine.
8: If he makes someone sad (like unintentionally making Little Miss Sunshine sad) (maybe because of his slightly proud pride in being happy), he apologizes right away.
9: There are times when he gets extremely angry, either because someone complains that he's annoying, or when someone steps on his foot, or because of Mr. Stuborn's And little miss stuborn's stubbornness.
10: she had a lucky red cap (Based on his 1980's redesign)
11: He and Little Miss Sunshine have a lucky red hat with a yellow ribbon and a red flower (similar to Little Miss Joyful's hat).
12: He and Little Miss Sunshine love hot chocolate, especially in winter.