Answer:
方 HOU, kata - direction
留 RYUU, RU, to(meru), to(maru) - fasten, hold, stay, settle
石 SEKI, SHAKU, ishi - stone
師 SHI - teacher, army
安 AN, yasu(i) - peace, cheap
They all take the "fish" radical (魚 GYO, sakana, uo - fish) to become other characters.
魴 hou, oshikiuo, kakamitai - sea bream
鰡 bora, ina, ryuu - grey mullet
鮖 kajika - bullhead
鰤 buri, hamachi, kamasu - yellowtail
鮟 an - anglerfish