Hmm.. I wonder which oomf sent this!! /silly I like to think she doesn't have the greatest fashion sense, so she picks out outfits that look kinda goofy, but ultimately catch on because everybody loves Mana and they'll still think she's cool anyways!
Also I like to think she's a little dense.. Like Regina (or whoever you prefer to ship Mana with) could be like "hey, Mana, let's go on a date" in the romantic sense and then she'd be like "sure! I'll invite the others, too!", not realizing it was meant romantically. Then her friends would be like "omg Mana, she meant it romantically, you goober!"