Who is Aqua and Rubi’s Father and Ai’s Husband?

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Ayush Rajan

Who is Aqua and Rubi's Father and Ai's Husband (1)

Oshi no Ko, made by Aka Akasaka who gained renown from Kaguya-sama: Love is War, is predicted by many to be the next big thing in anime. The manga has also been rapidly growing due to its mysterious and dark dive into the world of show business. The series follows a boy named Aqua and his sister Ruby who were both people that got reincarnated as the children of an Idol named Ai Hoshino.

While enjoying their second chance at life, tragedy soon strikes as their mother is killed by an obsessive fan. Ruby is seemingly able to move on from this incident and even tries to become an Idol herself. Aqua, on the other hand, is permanently scarred and goes into the entertainment industry in order to track down his father who he believes to be related to his mother’s death.

Ever since this was revealed, we see Aqua relentlessly chasing after the perplexing presence of his father who no one seems to truly know. Fans have also been extremely curious as to who this man really is. With recent revelations in the manga, we finally seem to have gotten some answers regarding this person who seems to be the main antagonist of Oshi no Ko.


Who is Aqua and Rubi’s Father and Ai’s Ex?

Hikaru Kamiki

The man who is the father of Aqua and Ruby Hoshino as well as the person who was with Ai Hoshino in the past is known as Hikaru Kamiki.

With two black stars in his eyes and an appearance just like Aqua, it is hard not to see the obvious relation between the two. Due to being assaulted as a very young child, it is implied that Hikaru is very mentally disturbed.

He is sadistic and cold and also enjoys murdering successful actors. At the same time, Hikaru is also a very smart individual who takes caution in order to not be caught. As a talented actor himself, he can easily adopt other personas and even uses the emotions of others to his advantage, with the most well-known example being how he guided the stalker to Ai Hoshino.

Watching the face-off between him and Aqua, who shares a lot of similar traits in regards to his calculating nature is a battle which everyone is looking forward to with bated breath.

Hikaru Kamiki Wiki

NameHikaru Kamiki
Kanji Name神かみ木き ひかる (カミキ ヒカル)
Rōmaji NameKamiki Hikaru
Height178 cm (5’10”)
Age33 (Movie arc)
Birthday27th July
OccupationTheatre Actor (Formerly)
Agency Owner
RelativesTaiki Himekawa (Son)
Aqua Hoshino (Son)
Ruby Hoshino (Daughter)
RelationshipsAi Hoshino (Former Girlfriend)
Airi Himekawa (Molester)
First AppearancesManga: Chapter 72


Hikaru Kamiki is an attractive man who shares a striking resemblance to his son, which led to a moment where Akane almost mistook him. Similar to Ai Hoshino and their children, who display darker aspects of their personalities and have black stars in their eyes, Hikaru also possesses this unique feature.

In public, Hikaru conceals his true appearance through various disguises, with particular emphasis on hiding his eyes. For instance, when he visited Ai’s grave, he donned a long overcoat, a hat, and sunglasses.

Hikaru Kamiki

On another occasion, while attending a high-class event, he opted for a black suit and sunglasses again. When interacting with Yura Katayose, he tied his hair in a ponytail and kept his eyes closed.

It seems that Hikaru prefers to maintain an air of mystery and anonymity in public, possibly to protect himself or those close to him. These disguises and concealment techniques give him the ability to move about without drawing too much attention to his true identity.


Hikaru Kamiki possesses a disturbing and twisted personality, characterized by sadistic tendencies and possible insanity. He takes pleasure in observing the life drain from his victims, who are predominantly successful actresses at the peak of their careers. This act provides him with a perverse sense of satisfaction, claiming it allows him to “feel the weight of his own life.” There is a dark implication that his troubled past, having been molested by a married adult actress at a young age, might have contributed to his current disturbed state of mind.

Despite his violent and murderous inclinations, there are hints that he had genuine feelings for Ai Hoshino, his former girlfriend, albeit in a deeply distorted and unhealthy manner. This conflicting aspect of his personality adds another layer of complexity to his character.

In public, Hikaru adopts a facade of being a dependable and ordinary individual, adept at concealing his true nature. This skillful act allows him to maintain a casual and approachable demeanor, making it easier for others to trust him. He also has a manipulative habit of sending white flowers to up-and-coming actresses, potentially as a means to draw in his next victims.

During his killings, Hikaru is meticulously cautious, taking great care not to leave any incriminating evidence behind. He chooses isolated locations for his attacks and inflicts injuries that could be mistaken for accidents, making it difficult for investigators to trace the murders back to him. He seems to operate on a careful plan, getting close to his targets through his public persona and only striking when the circumstances are perfect.

In the past, he relied on proxies to carry out his dark intentions, such as leaking personal information about Ai to a disgruntled fan and informing the actress’s husband about her affair. This suggests a pattern of manipulation and calculated actions to achieve his sinister goals.


When Hikaru was 15 years old, he and Ai Hoshino became parents to twins. However, their relationship didn’t last, and Ai now refers to Hikaru as her “ex.” Despite the breakup, Ai believes that their children will eventually come to understand the situation between their parents.

Hikaru was only 11 years old when he become Taiki Himekawa’s father with Airi Himekawa. Because of this, it is likely that Airi, who was already a married adult at the time, was the one who instigated their relationship, molesting and taking advantage of the boy. Taiki remains unaware that Hikaru is his biological father, believing it is Seijuurou Uehara.

Akane Kurokawa and Aqua Hoshino have pointed out that Hikaru could not be held accountable under the Japanese legal system for his involvement in the murders of Ai Hoshino and Airi Himekawa due to his status as a minor at the time. However, the situation could potentially alter if his recent murder of Yura Katayose comes to light.

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Ayush is a dedicated animanga enthusiast with a vast collection of experiences. With over 200 anime series and 300+ manga, manhua, and manhwa titles under their belt, Ayush's knowledge and passion are unparalleled.