Questions About these Quotation-Mark Placements

[DaSuperBaby]

This might come off as dumb, but why are quotation marks usually put around the 未来 mirai in “未来”トランクス ("Future" Trunks) and the 兆 kizashi in 身勝手の極意“兆” (Ultra Instinct "Sign"/"Omen")? I'm thinking it's just for placing emphasis on those words, but I'm not sure. I don't know whether or not this is a style I don't know about. Why not place quotation marks around the whole name 未来トランクス, or the 真 shin in 真の身勝手の極意 (True Ultra Instinct)?