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Come now, take my hand, Princess. It's embarrassing? Pft, it's okay. We're the only ones here. Hey, show me more of your face, Princess.
Kazuna is called MooNs' leader albeit reluctantly. Nevertheless, he takes his role seriously and is always willing to listen to others problems.
He is a tall, young man with beautiful features. His short hair is honey blond with his bangs parted to the right. He has turquoise eyes. Kazuna's right ear is pierced with two earrings.
His dress style is casual. He can often be seen with a sweater or shirts. Generally, he wears light colours.
Kazuna is the embodiment of a honour student: Smart, helpful and gentle. However, he also is quite competitive and has a jealous streak to his personality. He is very conscious of his actions and always tries his best. The urge to succeed in everything often clouds his mind.
An important aspect of his personality is his lack of self-worth. He does not deem himself special even though his group and Tomohisa think of him as a very capable person who they can rely on.
Not much has been revealed about his past. It was mentioned in Season 1, episode 8 that he searches for his mother. He hopes that she will find him one day if he continues to work as an idol. The circumstances about the disappearance of his mother have yet to be explained.
Kazuna joined Bambi two years earlier than Hikaru.
Tomohisa and Kazuna knew each other since their Bambi period and they hosted the Prodigy Brunch Special, a popular lunch show, together during their time there. Their relationship started out well. However, as time passed Kazuna felt inferior to his friend. He tries his best to act independent of Tomohisa but comes to his personal conclusion that he will always be outshined by his teammate. 
In contrast, Tomohisa is not of the same opinion. For him, Kazuna is a very capable person who has his own charm and shine and admires him, never missing any of MooNs' performances. He is not aware of Kazuna's conflicted feelings.
It was after the talk with Ryuji who questions his inferiority complex and noticing an annotated magazine about the food in Hokkaido in Tomohisa's bag that Kazuna had a better understanding of Tomohisa.
Momotaro loves and respects Kazuna a lot. According to Hikaru, Momotaro becomes unexpectedly talkative when it comes to Kazuna and often talks him up. He can also be considered one of the few people that can stop Momotaro from going too overboard.
Although the trust is mutual, Kazuna's habit to shoulder everything by himself often makes Momotaro worries about him and wishes his beloved Leader would rely on him more.
Kazuna and Tsubasa have a relationship build on trust and respect. He always treats her in a polite manner and regards her as an equal.
His SSR「Honest Feelings」reveals that he is currently not interested in romance since his career takes first priority. Despite that statement it has been vauguely implied on different occasions that he holds some affections towards Tsubasa.  One of the recurring subjects of his cards are their chance encounters. They make clear that he enjoys her presence and likes to spend time with her. However Kazuna can be sly at times as well. It is best shown in his SR「Glass Tree」 where they both go Christmas shopping together. At first it looks like a coincidence but he later asks her to keep it a secret from the other members. Usually Kazuna doesn't mind sharing with the other MooNs members but at those moments he tends to become a bit selfish to be alone with Tsubasa. Though, there is also a bashful side of him. He sometimes reacts awkwardly and blushes when being complimented by her.
An important aspect of their relationship is Kazuna's comfort in Tsubasa's presence. He tends to lose confidence in his proficiency and doubt himself during a job. Because she knows about this habit she often reaches out to him, asking how he is feeling and what his thoughts are. Tsubasa tries to encourage and support him the best she can. Her words help to lift his spirit. Sometimes, she teases him a little for being a worrywart.
Nozomi is Kazuna's only sibling. The both of them had not met up for a very long time, way before Kazuna's debut, and since Nozomi moved to Tokyo. As Kazuna loves his brother dearly, each time Nozomi turns him down their planned meetings last minute due to his work, Kazuna gets dishearten despite growing physically and mentally into an adult.