They have almost the same vibe!! But the boy next door is bromance and kieta hatsukoi is bl. There're some funny misunderstandings and soft, really enjoyable stories/characters
Both dramas display the same type of humour. While Diary of Tootsies shows gay people. The Boy Next Door is technically not a gay drama. But does portray gay-ish themes.
Short episodes with a great focus on comedy. Hilarious but sweet. Amusing misunderstandings in both. but there's more of a focus on that type of humor in The Boy Next Door. Great relationships in both.