Chin Gentsai is a character from King of Fighters. He marks the official debut in the Metal Slug universe in Metal Slug Defense as a KOF20th Anniversary Collaboration Campaign.
He is the elderly mentor to Athena Asamiya, Sie Kensou, and Bao, who instructs them to better harness their psychic powers (or Psycho Powers as it is dubbed by SNK) in the mountains of China. Chin teaches them in preparations for "the worst case scenario of oncoming evil" and uses the tournaments as a way of training his disciples. For a time, he was skeptic that their fame won in the tournaments crippled his students' determination and wanted to continue their secluded lifestyle. However, they convince him otherwise and has since believed in his students.
Things take a turn for the worse with the introduction of the Dragon Spirit between Bao and Kensou, with Chin having suspicions on the cause of its emergence. Although both boys were weakened because of the spirit, the old master entered them in the tournament in an attempt to recover their strength. He eventually pulls the team out of competition in 2003 to observe the matter thoroughly, asking K' and Maxima to investigate the tournament in his place for activity. During the year of the team's absence, he extensively trains Kensou's budding psycho powers -which were regained mysteriously after 2001- to be normal again. Prior to the KOF XIII tournament, he became e-mail and cellphone buddies with Kula Diamond, which is humorously mistaken by Kensou to be a secret love affair. Chin asks Kula to enter the tournament with K' once more, calling the young man out of curiosity to gauge his reaction.