Shōta Ōhara, the second son of the Ōhara family and a human elementary school student, discovered Q-Taro's egg in a forest during a ninja game with friends. He accidentally hatched the ghost by cracking the egg open. Initially confused and annoyed by Q-Taro's presence, Shōta gradually formed a deep friendship with the ghost after receiving repeated help. He later facilitated Q-Taro's acceptance into the Ōhara family, though he first hid the ghost from his parents.

Standing 135 cm tall, Shōta struggles academically, having ranked second from the bottom in his class. His relationships include classmates like Yoshiko Koizumi, for whom he harbors affection; Tsuyoshi Saigo (nicknamed "Godzilla"), a neighborhood bully and rival for Yoshiko's attention; Kizao Kiza, a wealthy peer often siding with Tsuyoshi; and Hakase, an intelligent classmate collaborating with Shōta on research. Shōta also experiences occasional clashes with his older brother, Shin'ichi Ōhara, though they coexist as siblings.

Shōta and Q-Taro share a bond of mutual assistance during troubles, though their friendship includes frequent arguments. Shōta often intervenes to correct Q-Taro's misunderstandings of human society, which frequently trigger chaotic situations. He also maintains friendships with other ghosts in Q-Taro's circle: Q-Taro's younger brother O-jiro (despite Shōta being unable to understand O-jiro's limited speech), P-ko (Q-Taro's sister), U-ko (Q-Taro's girlfriend), and Doronpa (Q-Taro's rival).

In the manga's concluding storyline, a time skip reveals Shōta at age 25. Reuniting with Q-Taro after a 12-year separation, he attends a celebration for the ghost's return. Now an adult with a wife, Shōta realizes his matured life no longer aligns with Q-Taro's perpetual childishness, as ghosts age slowly. Recognizing their incompatibility, Shōta accepts Q-Taro's permanent departure to the ghost world.