Because Akiha is the only one of the Shishido sisters that made time to care for her when she was newly manufactured and brought to the Shishido household as a maid, Imoko is best friends with Akiha and has been adopted as the sixth Shishido sister. As a Naviman nicknamed as a potato because of her appearance, Imoko has the capability to interface and operate almost any electronic device which delights Akiha and has even saved her life on numerous occasions throughout the series. Imoko's willingness to sacrifice herself to rescue Kirkwood from an approaching anti-matter missile inspires Nerval to intercede and have a change of heart with how he recruits people into his Utopian plans. Even with room and board at the Orbital Cafe Enigma endemic with Nerval's intercession, Imoko's inability to return to Akiha with the insight she has gained from watching Nerval as he tries to understand humans proves crucial in Akiha growing into her role as the "Girl Who Leapt Through Space".
