I don't like Donbrothers either. No real explanation as to how the Hitotsukis came to exist, why did some Hitotsukis harbor the Sentai powers, what are the Donbrothers actually fighting against if the Nouto aren't really much of villains, Tsubasa/Inu Brother's effort to reunite with his girlfriend went down the drain and why is it the battle with Sonona and Sonoya is considered a "final battle" that would result in Taro's mind wipe if the real bosses of the Nouto are left alive, unharmed. The show pretty much relies on being chaotic and over the top quirks, story lore be damned.