Im writing this story and one of the characters calls his younger friend "little bro". (ex: You ok, little bro?) I've never heard of a term like that in Japanese so it might just be an english only term... Otouto is kinda weird since its like for telling other ppl that this is your little bro... I've read that otouto-chan or otouto-kun is only used if you're trying to be mean. Is there a nice term close to "little bro" that my character can use when talking to his little bro like friend? Thanks!!