|English voice actor||None|
|Japanese voice actor||None|
Takashi Takeda (Japanese: 竹田隆 Takeda Takashi) or "Jumbo" (Japanese: ジャンボ Janbo), is a friend of Koiwai and Yotsuba's, having known Koiwai since they were childhood classmates. He is the oldest out of Koiwai, himself and Yanda. Standing 210 centimeters (over 6 foot 10 inches) tall, Jumbo dwarfs the other characters, especially Yotsuba. He is always called by the nickname "Jumbo," and when Fuuka learns his real name she calls it "common." He works at his father's flower shop, as Yotsuba discovers when she meets him there. He helps the Koiwais move in and frequently visits their house, where he is more or less treated as a member of the family by Yotsuba.
Jumbo has a dry sense of humor and is prone to deadpan quips, which sometimes confuses members of the Ayase family. At the same time, he is impulsive, and sometimes spontaneously organizes activities for the younger children, such as fishing and star-gazing. As he does this, he enters a bizarre one-sided rivalry with Miura, including spending a single day in Hawaii after he learns that she will be going abroad, just so he could win against her. He develops a deep infatuation with Asagi when he first meets her, but is too nervous around women to directly act on it. Instead, he tries to use Yotsuba's friendship with Asagi as a way of getting close to her (which Koiwai disapproves of), though his plans usually backfire.