The oldest member of Koko's crew and the second in command. A former Delta Force operator who used to be active in Somalia during the 1990s, he is a veteran mercenary with strong leadership skills. He acted as Floyd Hekmatyar's bodyguard together with Chiquita, his ex-wife, before joining Koko's squad. Lehm also does sniper work either alone or together with Lutz. Lehm is probably the most dangerous of Koko's bodyguards along with Wilee. He was the only one to aim his weapon at Yonah when the latter threatened Koko. His surname "Brick" was reveled in ep7 of season 2. (Source: Wikipedia)
A former artillery officer from an Asian country, he was discharged from the military after a deadly training accident and was later recruited by Koko. He is the only member on Koko's team that has a family. He is put in charge of giving Jonah science lessons. (Source: Wikipedia)
A former police sniper who was once part of the counter-terrorist unit, until he becomes one of Koko's mercenaries. (Source: ANN)
CIA paramilitary operations officer plotting against Koko. Commits suicide before being bombarded by Koko's jets after R's death.
Natsu Takasaki is a member of Southern Tennis Club (STC). She is in the same year and high school as Maruo. She is aiming to become a professional player. Currently in season 2 and the manga, she's going out with Maruo Eiichirou. (Source: Baby Steps Wikia)
Ryuhei Aoi is a coach at Southern Tennis Club and primarily assists Eiichirou Maruo on his journey to become a professional. He is a ex-professional tennis player who retired after receiving an injury. Ryuhei has a calm personality and likes players to take it easy while working hard. He advices Eiichirou to depend on his instincts and knowledge both or he will lose all his skill and end up being weak. He also cares for his students and when stopped Eichirou when he tried fast serve without any prior training. (Source: Baby Steps Wikia)