Boo-chan, also called Bo or Boo, attends Futaba Kindergarten alongside Shinnosuke Nohara in the Sunflower group. He displays a perpetually slow, expressionless manner that suggests detachment, yet harbors sharp intelligence and surprising insights into artistic or mature topics, often startling classmates with his observations. His speech unfolds with deliberate slowness. A constant trail of mucus extends from his nose, which he adeptly manipulates into tricks.

His distinct hobbies encompass collecting uniquely shaped stones and probing urban legends, UFOs, and paranormal phenomena. He professes knowledge of Japanese locations yielding rare stones and routinely observes artisans at a Kasukabe tatami workshop. In group pretend-play, he consistently chooses to embody a pet dog or cat.

His family background is minimally detailed, with his mother appearing just once in official media, shown sharing affection with him; his father remains unseen. Within the Kasukabe Defense Organization, he stands as the tallest friend, primarily due to his elongated head rather than substantial height.

He shares close bonds with Shin-chan, Masao, Kazama, and Nene. Boo-chan exhibits notable patience with Shin-chan’s antics, joining his imaginative games readily. He comforts Masao during distress and garners Shin-chan’s occasional praise for intelligence rivaling Kazama’s. He and Nene offer mutual support consistently. A future depiction in "Super-Dimension! The Storm Called My Bride" shows him as a mid-twenties roboticist and inventor. His real name, Botarō Ikawa, surfaced during an anime sumo tournament episode.