Satoru Watabe is an elite diplomat from the Ministry of Foreign Affairs whose duties include collaborating with the Ministry of Health, Labor and Welfare and various police departments on drug control operations. He possesses an easygoing and lighthearted personality that often makes him a moodmaker within his unit, yet he demonstrates seriousness and sharpness in professional settings. He does not allow his relaxed demeanor to interfere with his work.

He openly acknowledges being a lightweight when it comes to alcohol and never pressures others to drink, instead preferring to invite colleagues to relax in social situations. Watabe maintains a distinctive beard intentionally, believing it makes him appear older than his actual age, though he finds facial hair somewhat cumbersome for his current role.

When discussing his profession, he notes that being a diplomat has advantages such as attracting romantic interest and providing opportunities to travel overseas for work. His future aspiration is to live together with a significant other. In social interactions, he occasionally makes playful remarks, suggesting that someone might have developed feelings for him.