Hitoshi is Nana Takahara's manager who is in love with her, but can't bring himself to tell her.
Hitoshi is first seen during a concert of Nana's. 
He is a childhood friend of Nana's, as well as her manager, but he is very much in love with her and wishes to propose marriage that evening, after the concert. Kinnikuman sees Hitoshi distressed - after he tries to propose and fails - and Hitoshi reacts coldly to his sympathy, by destroying some of Kinnikuman's cherished merchandise. When they are finally alone, Nana asks him to tell her what is on his mind. 
Nana reveals she has feelings for him, enough that she asks for a kiss, but he is too nervous and cannot oblige, at which point she slaps him. Later, when Hitoshi sees Nana has been kidnapped by Gorizaemon, he tries to attack Gorizaemon and scale the building to rescue Nana. Hitoshi is injured and knocked unconscious, but - when he awakens - he attacks Gorizaemon's also unconscious form, which leads Nana to wake up and see these actions. Nana assumes Hitoshi was thus the one to rescue her from harm. They then finally embrace with love.