Nagasumi's father (永澄の父 Nagasumi no Chichi ) (Michishio, first name not known) is the father of Nagasumi and husband of Nagasumi's Mother.
Appearance
Nagasumi's father is a tall, muscular man with short black hair which is similar to Nagasumi's, and has black eyes. He is often seen wearing a solid tan green short with short pants and slippers, also throughout the series he is seen wearing his glasses.
Personality
Nagasumi's father is always shown as an object of suffering, due to his wife's dying love for him. Whenever his wife shows her interest in Masa, he is shown in a depressed state, like the time she offers Masa her home cooked meal, he is shown coughing on a burger and then subsequently harangued by his boss to get back to work.
Like his wife he is also shown to be very neglectful and abusive to his son since he considers him a looser and disgrace to their family and favors Sun more. He considers Nagasumi “useless” for his failures while never putting in any effort to be a real father or help him. Often leaving him to deal with his own problems (even life threatening) and furiously beating him over his mistakes. In the first episode, he even uses Nagisumi as a human shield to protect himself from Suns father and before then expressed more annoyance than concern over his son drowning and claiming he was saved by a mermaid.
Like his wife, he is always willing to believe the worst about Nagasumi and punish him without considering he was wrong (and never apologizes when he learns he was). He readily jumps to beat Nagasumi whenever he accidentally peeps on someone and calls him a pervert despite Nagasumi always telling him they were accidents. When they found a mermaid porn video and he encouraged Nagasumi to watch it together, only to learn that it was just fish, he instantly believed that Nagasumi knew all along and accused him of having a weird fish fetish. In the anime, he called Nagasumi “Naughty-sumi” to mock or insult Nagasumi for his supposed pervertedness.
Unlike his wife who occasionally shows some concern for Nagasumi, he honestly shows he doesn’t care about his son at all. In episode 12, he outright gives Lunars dad permission to kill Nagasumi and dismissed his son’s potential death as an “unfortunate accident” to forget about. In a chapter of the manga, he tells his wife to ignore Nagasumi (who is frozen and possibly dead) in favor of her calling an ambulance for the cuts on his chest. And when under the effects of a potion that caused him to see Nagasumi as something they hate, he repeatedly punched his son in murderous fury while telling him to die. While he didn’t seem to attack Nagasumi again after he collapsed to the ground unconscious, he did seem to actually want to murder his son for a brief moment.
Like his wife, he favors Sun and Lunar more than Nagasumi and sees them as daughter figures. However, he also seems to have some degree of attraction toward them. In episode/chapter 4, he admitted that if he could peep on anyone, it would be Sun. And in episode 12 he watches Sun working out with Lunar along with Nagasumi.
Despite this, in one manga chapter he was more upset at his house being destroyed than Sun being kidnapped. Also, a lot of his favoritism for Sun comes from the fact that she gives them money to pay for any damages and never asks them for any help (unlike Nagasumi).
However, it is implied that his rotten personality traits comes from a strained childhood. In the first episode his mother is shown to think as little of him as his wife does (to him and their son). Also, while he accuses Nagasumi of being unreliable he gets defensive when Nagasumi calls him so, indicating some insecurities that he projects onto his son.
One good thing that can be said about Nagasumi’s father is that he is extremely disgusted by the idea of peeping on other people when they are naked (whether it be Sun, Maki, or even Gozaburo). Sometimes hitting Nagasumi because he thought he peeped, groped, or did something else inappropriate with them intentionally.
However, when Nagasumi was under the effects of the mermaid love potion (which causes any man who looks at him to see the thing they despise and fly into violent rage) rather than seeing Nagasumi as a grotesque jerk who mocks him like every other man did, he instead saw a crudely drawn version of Nagasumi with a snotty nose speaking like a little kid. Also, while he “only” punches Nagasumi in the face when he is accused of peeping on girls, he beat him much more viciously when he thought he peeped on the Seto Gang (which they considered abnormal). This shows that he hates Nagasumi being an embarrassing fool that could reflect on him as his father more than he is disgusted by being his belief that he is pervert. Also that it doesn’t matter to him if Nagasumi is malicious in his intentions or not. He also beat Nagasumi in the first episode/chapter when he thought he was embarrassing him. After Maki lied about Nagasumi intentionally peeping in her and Sun, he claimed that he would rather die than people know Nagasumi is his son. Though the sincerity of this is debatable given how cowardly he is, this also suggests that a lot of his rage towards Nagasumi’s actions (perverse or otherwise) is because he feels his sons actions reflect on him rather than just moral standing. He also became furious when his wife, imitating Nagasumi, accused them of being similar (like father like son).
It is also noted that he still loves his wife, despite her waning interest in him, and never considers cheating on her. Only missing the days when they were younger and she still loved him.
Powers and Abilities
There is one ability Nagasumi's father has a passion for which is his legendary left hook he posseses that is said to be extremely powerful, leaving a terrible mark for days on his victim, showing its power. He reveals this in the first episode when he punches Nagasumi when hearing Sun ask Nagasumi to marry him and he quickly mistakes that Nagasumi was in a sexual relationship with Sun which quickly leads to him punching Nagasumi. But there is a draw back to this punch as stated by Nagasumi's Mother that this can be only used once a day.