Komasan Sun Ce can be picked as the main protagonist of the story. If Jibanyan Liu Bei or Usapyon Zhongda are chosen instead, Komasan Sun Ce can be automatically befriended during the story.
Unlike Jibanyan Liu Bei and Usapyon Zhongda, Komasan Sun Ce admires Whisper Kongming for being knowledgeable and helpful. Whenever Whisper Kongming messes up on something, Komasan Sun Ce tries to cheer him up.
(Japan) Link Yo-kai Sangokushi with Yo-kai Watch 3. Then, go to either Lambert Post Office or Skycutter Post Office to receive the Promise Pie. (International) Head to Piggleston Bank or Acornia Bank and scan the QR Code to the right. The QR Code will give the player the Promise Pie.
Head to Blossom Heights and go to Old Mansion - Side House.
Talk to either Jibanyan Liu Bei, Komasan Sun Ce, or Usapyon Zhongda. The player will be challenged to a battle with all three Yo-kai.
If the player does not befriend Komasan Sun Ce during the battle, they must wait for the next day to get another chance at befriending him.