Ebitani is a young blacksuit subordinate on Team Tonegawa within the Teiai Group. He joined the organization around the same time as Jirō Saemonsaburō, fostering a perceived rivalry due to their similar ages and entry periods. His surname, meaning "shrimp valley," reflects his distinctive personal motif; he incorporates shrimp imagery into his clothing and work presentations.

Ambitious yet impulsive, Ebitani struggles to grasp broader contexts, often fixating on minor details. This results in overly elaborate, impractical proposals, like advocating a restaurant venue for Restricted Rock-Paper-Scissors with 100 reasons while ignoring critical project requirements. His lack of situational awareness leads to termination after he directly approaches Chairman Hyōdō during a poor mood to request handprints for game cards—a severe miscalculation that also causes salary reductions for his superiors.

Following his termination, Ebitani attempts to redeem himself by aiding Tonegawa, but fails and plunges into debt. He then tries to damage Teiai's reputation through critical tweets on social media, revealing confidential details about cafeteria food and Tonegawa's appearance. His lack of discretion leads to capture when he posts criticisms while physically near Teiai's building. As punishment, he is imprisoned and coerced into building Teiai's official Twitter following to over 100,000 users before release.

Ebitani eventually rejoins Team Tonegawa as a replacement for another member. His later trajectory involves leaving Teiai to establish a small shrimp roll shop in Nerima, where he achieves business success. This post-Teiai phase shows a significant shift in his personality, described as fundamentally different from his earlier demeanor.

A notable personal oversight occurs when he sends Tonegawa a New Year's card during a period of mourning, highlighting his persistent difficulty with social cues and appropriate conduct.