Komasan Son Saku can be picked as the main protagonist of the story. If Jibanyan Ryubi or USApyon Chutatsu are chosen instead, he can be automatically recruited within the story. In yo-kai watch 3 he can be befriended by linking yo-kai watch sangokushi with yokai watch 3 sushi or tempura and can be found in the Old mansion shed.
Komasan Son Saku's Medal is included with the game.
After beating the game, when being called back to the book of Sangokushi, he's the only one of the 3 choices who does attack Whisper Komei.