Oh fuck, don't even get started on that. It seems they boil down to certain types
arrogant smug assholes
Ditzy useless girls, who sometimes are walking deus ex machina's with hidden powers activated by love or something
Violent tsendure who hoplessly love the main character, who is usually the...
Headstrong idiot who charge in recklessly and win through pure determination
All of these *can* be made into interesting characters if they're allowed some backstory or depth or any actual motivation. Typically they're just rubber stamped tropes though.
Spike was a bit of an arrogant asshole mixed with reckless charging guy, but he mostly didn't give a shit about living because of Julia. That works, it's endearing.
Kamina faked confidence to get Simon to feel more confident, who in turned lifted Kamina's spirit. That's great.