Nao Kiyomiya (清宮尚, Kiyomiya Nao) is a supporting character in the Sekai-ichi Hatsukoi series. He was Ritsu Onodera's high school roommate when Ritsu studied abroad.
Nao has dark hair and light eyes. He is close to Takano's height.
Nao is very friendly, at least when around Ritsu, and loves taking pictures. He enjoys teasing Ritsu by telling embarrassing stories about him from high school and also commenting that Ritsu had always been a slob. However, he is also protective and sympathetic to what Ritsu went through and cares for him deeply. He quickly picked up on the fact that Takano was actually Ritsu's high school crush and became extremely hostile towards him.
Nao's personality is very similar to Yokozawa when it comes to Ritsu. While he may have no romantic interest in Ritsu, he does share an identical relationship with him that Takano has with Yokozawa. Both are protective of their respective friends and show hostility towards the person responsible for their friends pain. Except, Yokozawa has made his peace with Ritsu, whereas Nao continues to show hostility towards Takano for breaking Ritsu's heart. It is later revealed that Nao actually does have unrequited romantic feelings for Ritsu.
Around Takano however, Nao acts extremely aggresive and clearly shows that he despises him. He often insults Takano and tries to get him to stop interacting with Ritsu.However, Nao is very good at hiding his feelings toward Takano and acts friendly again when Ritsu is nearby.
Nao and Ritsu were roommates in high school after Ritsu left Japan to study abroad. Ritsu was a mess after his breakup with Masamune Saga, and Nao helped him get back on his feet. The two became close friends, although nothing happened between them.
Nao and Ritsu run into each other at Marukawa Publishing when Nao is working on getting a book of his photography published. The two start to catch up, and they exchange business cards to keep in touch since Ritsu needs to get to a meeting.
That evening, Nao calls Ritsu and asks to crash at his place since he's only in the area for a short time, and Ritsu agrees. Nao comes over and teases Ritsu about having a messy apartment, saying he hasn't changed at all. Then Takano comes over, since he had plans on having dinner with Ritsu. The three eat as Nao and Ritsu catch up. During the conversation, Nao suddenly asks Takano if he knows why Ritsu went to study abroad, unknown to him that this is a tense subject for the two. Nao goes on to tell Takano how gloomy Ritsu was after his breakup. Ritsu tries to get him and Takano to stop, but Takano wants to hear more about Ritsu's "melancholy student life," and Ritsu half-slips that it's Takano's fault.
Ritsu leaves to get a bath ready, leaving Nao and Takano to talk. Nao goes on about Ritsu and what a "scumbag" his ex was, saying it was pretty clear that the guy was only ever using him, which angers Takano. Nao then asks about his name, guessing that he's actually "Masamune Saga." Nao digs into Takano more, distrustful of him after what Ritsu already went through because of him.
Ritsu comes back from preparing a bath, but they've talked so long that it's time for Nao to catch his train.
The next day at work, Nao takes a picture of Ritsu to commemorate their reunion before going.
Ritsu was Nao's roommate in high school. Seeing as Ritsu was having nightmares about "Saga-sempai", Nao decided to try to help and befriend him. Though it was difficult due to Ritsu's cold demeanor, Nao eventually got Ritsu to open up to him.
One night, when Ritsu was having a nightmare in the dorm room, Nao pressed Ritsu to tell who the "Saga-senpai" he was yelling about in his dreams was. Annoyed and not wanting to answer, Ritsu ran outside and they got in a physical fight, with Nao striking the first move. After the brawl, they end up opening up to each other. Nao told Ritsu about his little brother that died in a car accident when Nao was about twelve, and that Ritsu reminds him of himself at that time, and that's the reason he wants to help Ritsu. Ritsu then tells Nao about "Saga-senpai', which leads Nao to sympathize with Ritsu.
Years later, when Nao and Ritsu run into each other at Marukawa Publishing, they catch up and Nao ends up crashing at Ritsu's place in the evening. Nao finds out about Ritsu's boss being "Saga-sempai", now known as Takano Masamune, when Takano invites himself over to Ritsu's place and they all end up having dinner together. Nao ends up leaving early, telling Ritsu that he'd see him again.
When Nao says over to Ritsu's house again, they catch up while eating dinner. When Nao asks about Ritsu's love life, Ritsu quickly changes the topic and asks if Nao has anyone special in his life. Nao says that he's single, with his job causing long distance relationships, but that there is someone he likes. When Ritsu probes futher about the topic, Nao descibes the person as being "rather thick headed", strongly opinionated, and that it's an unrequited love. Being a bit dense, Ritsu asks if Nao is sure about that person and wants to be caught up with this "weird" person. Later in the night when Ritsu is asleep, Nao pats Ritsu's head and whispers that Ritsu is really a thickhead, hinting that Ritsu was the one he was talking about.
The next day, Ritsu finds Nao and Takano inside a cafe. When Ritsu goes over to greet them, he accidentally overhears Nao saying that he's in love with Ritsu. Nao then leaves the cafe after, leaving Ritsu puzzled about how to feel.
The next day at work, Nao confirms it and tells Ritsu that he meant what he said yesterday, that he likes Ritsu "in that way". He then laughs at Ritsu's surprised reaction and leaves, once again calling Ritsu thickheaded.
Nao first encounters Takano when they have dinner together at Ritsu's house. After suspecting that Takano is "Saga-sempai", he guilts and insults "Saga-sempai" for making Ritsu suffer in the past, and gets Takano to admit to being Masamune Saga. He then questions Takano's relationship with Ritsu, and accuses Takano of trying to hurt Ritsu again. This starts Nao's hatred for Takano, as he assumes that Takano wants to convince Ritsu to get back together with him and pretend like he never hurt Ritsu in the first place. He tells Takano that he's still doing a cruel thing to Ritsu, and that Takano doesn't deserve to have any explanation of how rough that time was. Nao then leaves Ritsu's house after the dinner.
Later when Nao invites Takano for a cup of tea at a cafe, Nao uses this opportunity to tell Takano to back off from Ritsu. Nao then confesses that he loves Ritsu and wants Takano to stop because he's already hurt Ritsu enough. The feeling of distaste and anger between Takano and Nao is mutual, and they develop a rival-like relationship.