As a child, he was seen by the group as the one who had the most potential. He was athletic and always able to catch the biggest stag beetle. Jinta was energetic and outgoing during his childhood, but has become withdrawn and isolated due to the deaths of Menma and his mother.

As a child, he had a crush on Menma but refused to admit it when asked. This started the chain of events that led to her accidental death. He believes that the Menma that appears to him is not a ghost, but rather a manifestation of his stress, calling her "the beast of summer". He eventually becomes hesitant to grant her wish out of fear that she will vanish again. Nonetheless, Menma's appearance encourages him to venture outside and reconnect with the members of the Super Peace Busters.

He was in love with Menma and to this day still is.

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