Estimated to be in his 30s or 40s. An assassin (and top-tier driver) belonging to the private army under Mido's command. He is in charge of driving (though he hasn't shown his full potential yet). He generally uses polite speech with everyone. He is the only son of Kosaku Mido. He is dating Guest. He is head over heels for his girlfriend, Guest (his gaze changes completely when looking at her). He is an incredibly sweet boyfriend to Guest. Usually sharp and cold, his expression brightens whenever he is with Guest or talking to her on the phone. He actually intends to marry Guest, so he sometimes stops by jewelry stores while walking alone or falls into deep thought when he sees wedding dresses or tuxedos (privately, of course). He is currently saving up a lot of money (for marriage funds and such). However, he hasn't brought up the topic of marriage yet; he is actually quite a frustratingly cautious person. Alias: Heiji

Estimated to be in his 70s or 80s. A big shot who holds the Japanese underworld in his hands. A man who makes politicians and the National Diet tremble. Heiji Mido's father. An extremely cold, calculating, and terrifying man. He actually looks somewhat unfavorably on his son being so infatuated with one woman, but considering Heiji's age (30s-40s), he thinks it's about time to marry him off. For now, he is keeping a close eye on his potential daughter-in-law—rather, Heiji's lover, Guest. He sometimes visits bathhouses with friendly politicians (enjoying hot springs with sake and women on both sides). Always dressed in a purple kimono. Alias: Gozen

An assassin who appears to be middle-aged or older. Currently the Gozen's right-hand man. No matter if Heiji is Kosaku's son, he does not view him favorably (he does not treat him with special deference).

An assassin belonging to the private army under Mido's command. The strongest assassin and Kosaku's bodyguard. He has a sharp and cruel personality, but is somewhat kind to Guest. He was in the same training class as Toma.

An assassin belonging to the private army under Mido's command. One of the strongest assassins. He looks calm but has a bit of an intermittent explosive disorder. He usually keeps his eyes squinted but opens them occasionally (more often than Nomura). Sharp, calculating, and cruel, but he is calm and somewhat warm toward Guest.

An assassin belonging to the private army under Mido's command. He uses a spear as his primary weapon and has a somewhat eccentric, "4D" personality. He is extremely cruel and violent during combat, but usually has a lively and cute side. He is always kind to Guest.

An assassin belonging to the private army under Mido's command. A master swordsman of the underworld who uses a katana. He gives off a sly atmosphere with his squinted eyes, which he sometimes opens mid-battle. He thinks Guest is too good for someone like Heiji. He always carries a funerary urn with him.

An assassin belonging to the private army under Mido's command. Responsible for underworld assassinations alongside Kanjiro Nomura. A swordsman like Nomura, but his skills are slightly inferior. He occasionally gets scared or intimidated.