Kaiyo Yufuin

Kaiyo Yufuin is is a character in Cute High Earth Defense Club series. He is En Yufuin's older brother, a talent agent at MILKY POP Industries, and the eldest son of the Yufuin Family.

In Arc 1 Episode 12 - Love Forever, it is revealed that he was a Battle Lover himself way before the 8 main protagonists became so. He was well known in the first CIDE battle as Maximum Kaiyor and wielded a long sword.

Appearance
Kaiyo in his high school years had short dirty blonde hair and a sea dragon shaped tattoo on his left hand. He wore the Binan High 3rd year uniform in a disorderly fashion, further signifying his "delinquent" look, using his tie to cover his tattoo. As Maximum Kaiyor, his outfit was blue and white, similar to En's, but with long pants and boots, a double-breasted trench coat, and a much more mature princely appearance. He also had a blue Loveracelet which he still keeps around, despite saying that he wouldn't want to be a Battle Lover anymore.

As an adult, it seems he has gotten out of his delinquent phase. He is mostly seen wearing white shirt, a blue suit jacket, black work pants, black knee-high boots, and work glasses with a white frame and blue-colored lenses.

Personality
As a teenager, Kaiyo was very much a "cliche" delinquent student throughout his three years of high school as a result of his and En's parents leaving them for work all the time, causing him to despise them and had to become a parent figure himself to En. One of his only friends at the time was Souta Kinugawa, Atsushi and Teara Kinugawa's older brother and the only person he had thought he had felt he was comfortable around. He also confided in the school infirmary doctor Kurou Hara at the time, seeing him as a father figure better than his own father. When Gora and Shoebill (as a human) ask if he wanted to join the Battle Lovers, he at first asked if they're delusional. However, when Shoebill showed his true form, he immediately thought that he was having a fever dream, proving that Kaiyo has more or less a realistic mindset. He joined the Battle Lovers, who were then named Maximum R.

As a Battle Lover, Kaiyo was more interested in the fighting than worrying about the bystanders. This seemed to have added to the delinquent personality even more. He claimed he barely got along with Kaname Kaidou, the eighth heir due to his element and so-called "haughty" attitude. When Kaname had becomes a Loveless and disappeared, Kaiyo says that he never liked him anyway which seemed to be what had caused the rift in Maximum R in the first place. This turns out to be a lie, as he then confesses that he had developed romantic feelings for him, showing that he had a bit of a tsundere personality trait but was afraid of being rejected. Ten years later, he is no longer a delinquent but has been keeping his Loveracelet in his mother's old jewelry box. Kaiyo is barely around at home due to him landing a talent agency job so he basically let En do whatever he wanted once he had hit fifteen years old. When he comes home and sees Seto (Uta in CHEDCP), a so-called "girl" in En's room, he immediately gets angry and questions En, with him lazily responding that "she's just a friend", showing a overprotective parental side to him.

His relationship with En was at first distant due to En always saying that Kaiyo became just like their father and mother, with Kaiyo always shouting back that he hasn't, causing many arguments between the two of them. After Kaiyo finds out about En being a second generation Battle Lover, he tries to tell En to stay away from Yumoto and the others, with En retorting with, "like you did?", referring to how after Kaname disappeared, he had distanced himself from Gora and the other Maximum R members after he had graduated high school. This then lets the Beppu Brothers turn him into a Loveless because of his heart becoming so corrupted due to years of melancholy without any parental love. As a Loveless, Kaiyo is much more expressive with his negative emotions, saying that he would drown the entire world in an "abyss of sorrow" and take everyone else with him. En manages to get through to Kaiyo and uses the True Love Attack and True Love Fountain to bring him back to normal, leaving him feeling much better and refreshed. He apologizes to En about lying to him and all of the fighting, saying he was proud that En was becoming a responsible adult, and the Yufuin brothers embrace while Kaiyo's Loveracelet gains its bright blue color back, signaling that Kaiyo's heart had been changed.

History
During his high school years, Kaiyo was a Battle Lover who defended Earth when Hireashi had attempted to create an Earth-centric reality show called Can I Destroy Earth? However, their plans and show were thwarted by the Battle Lovers known as Maximum R, who had always defeated all the monsters Hireashi sent. Eventually this caused the show to lose its popularity and it was eventually canceled, also causing Hireashi's downfall.

Although Maximum R were introduced as villains (such as modifying what they said and depicting Earthlings as ignorant and stupid beings), they gained a good number of fans due to their persistent nature. So much so that the producers canceled the show when they saw that the audience loved the "antagonists" more than the monsters. Sometime after it was canceled, Kaiyo landed a job at MILKY POP Industries as a talent agent.

Relationships
Gora Hakone- Gora was Kaiyo's junior at the time, so he always referred to him as "Kaiyo-senpai". The two of them trusted each other as teammates and friends so they had a good relationship.

Ryite Naruko- Ryite was Kaiyo's junior at the time, so he always referred to him as "Kaiyo-senpai". The two of them trusted each other as teammates and friends so they had a good relationship.

Souta Kinugawa- Both of them were in the same year and always referred to each others' names without any honorifics, showing a strong bond of trust between them.

Hinote Zaou- Hinote was Kaiyo's junior at the time, so he always referred to him as "Kaiyo-senpai". The two of them trusted each other as teammates and friends so they had a good relationship. Throughout the series, Hinote was always shown having a crush on Kaiyo.

Hoshi Ghaunam- Hoshi was Kaiyo's junior at the time, so he always referred to him as "Kaiyo-senpai". The two of them trusted each other as teammates and friends so they had a good relationship.

Chantal Fredonia- Chantal was Kaiyo's junior at the time, so he always referred to him as "Kaiyo-senpai". The two of them trusted each other as teammates and friends so they had a good relationship.

Kaname Kaidou- Both of them were in the same year. The two of them had a "love-hate" relationship at first and only trusted each other as teammates.

En Yufuin- Kaiyo's younger brother. The two of them were very close as children, but when their parents started to not be around, the two of them became distant and Kaiyo becomes overprotective of him on his side, which could be the reason for En's lazy behavior. This may have also alluded to a developing brother complex.

Yumoto Hakone

Io Naruko

Atsushi Kinugawa

Ryuu Zaou

Nozomi Ghaunam

Seto Kaiba

Uta

Kyiki Hashimoto

Wombat

Shoebill

Etymology

 * Kaiyo's name means forgiveness, foreshadowing how the two Yufuin brothers would make up.
 * Kaiyo's surname Yufuin means "reason, case, cause" (由) (yu), "cloth" (布) (fu) and "hospital" (院) (in).
 * Yufuin is derived from an onsen (hot spring) resort in Japan located about ten kilometers inland from Beppu, another much larger and more developed hot spring resort.

Trivia

 * Like Gora, Kaiyo keeps his form after turning into a Loveless. This could mean that if any former or current Battle Lover becomes a Loveless, they still keep their normal body shapes.
 * The tattoo on his hand may have meant that he was at one point a part of the Sea Snake Mafia and he never told En or his parents or the other Battle Lovers, not wanting them to get involved. It's unknown if he is still involved with them or left after he graduated high school.
 * The reason he dislikes snow is because one year he had caught a cold during the winter months and his element water never worked during that time.
 * Like En, Kaiyo has long eyelashes.