マ+用 Katakana "Ma" / YOU, mochi(iru) - use, business
制 SEI - system, regulations
希 KI - hope, desire, scarcity, rarity
昌 SHOU, atsu, akira, utuku(shii) - bright, beautiful
反 HAN, HON, tane, so(ru) - anti-, bend back
They all take the "fish" radical (魚 GYO, sakana, uo - fish) to become other characters.
鯒 kochi - Bartail Flathead
鯯 SEI, sappa - Dotted Gizzard Shad
鯑 kazunoko - herring roe
鯧 managatsuo - silver pomfret
魬 HAN, BAN, hamachi - Immature Yel