Ein mysteriöser Mann besucht das Labor. Er ist auf der Suche nach einem entlaufenen Roboter-Hund. Hiroshi und Umataro bieten an, ihm mit A106 dabei zu helfen.
A multipurpose private detective investigating in lab 7's junkyard is caught by A106, Ran and Ummataro who brand him as suspicious and inquire about his intentions while Hiroshi returns with Motoko turns out Motoko and detective (who identifies were Kensaku Han) are acquaintances. Han tells them that he is searching for a robot pet named Malon which has a huge reward; Motoko pipes in that if Han wants to find the pet he should hire boys as campus is very large, difficult to warfare and exclusive to students, Ummataro agrees to the offer finding it as it was a good opportunity to test A106's new sensors, Han reprehends by saying that robots aren't qualified for such jobs causing a spat with Ummataro to which both make a bet. Hiroshi, Motoko and Han search around campus employing old fashioned legwork Motoko asks him about the person who made the request to which Han explains the man might have had strong emotional attachment to the pet, while searching Motoko bumps into an old man who lost his way around. Meanwhile Ummataro and Ran use A106's sensors to search for devices using old network technology used by the pet to communicate during which the come across the same old and find a similar pet in his bag, the man turns out to the client; both teams put two and two together to discover only one hit was remaining at the construction site where A106 finds Malon returning it to its owner.
第７研究室にやってきた怪しい男。それは便利屋「マルヒゲ」の伴 健作だった。健作は、依頼を受けて、ペットロボット・マロンを探していたのだ。そこに茂斗子も姿を見せて、午太郎と博志をアルバイトで雇い、A106を使うことを提案する。ところが健作は、探偵は人間にしかできない仕事と主張し、Ａ106をロボット探しに使うことに反対する。「よし、じゃあＡ106と勝負しろ！」。天馬たちと健作の探偵勝負の行方は？
Un uomo cerca qualcosa nell'università di Nerima. Umataro e Hiroshi sono a corto di fondi e Motoko vorrebbe aiutarli. Un'originale indagine coinvolge il laboratorio 7.
