HitsuKarin is the name of the relationship between Toushiro Hitsugaya and Karin Kurosaki.
The Arrancar ArcEdit
In episode 132, Karin was worried about her brother, Ichigo, which made her feel frustrated and accidentally kicked her soccer ball too hard, causing the ball to fall towards the nearby road. Karin, who was chasing after her soccer ball, stopped, when she saw someone (Toshiro) pick up her ball. Toshiro then told Karin to be more careful as he returned the ball to her and disappeared.
Later, it is shown that Karin wanted to play soccer with her friends but the middle schoolers are not willing to give up the field. Angered, Karin ended up arguing with the middle schooler through the afternoon until one of the middle schoolers suggested that they should settle it with a soccer match. She had accepted the challenge. On their way home, Karin met Toshiro again and she ran towards him and thanked him for picking up her ball earlier. When Karin asks Toshiro to join their team, Karin's friends were shocked and told her how a midget like him (Toshiro) could be good at soccer. Angered after being called a midget, Toshiro begins to walk off. Karin then kicks her ball at Toshiro and he surprised them by returning it with his kick. As the kids gathered around Toshiro in amazement, Toshiro notices Karin seemed to sense something when he gets a Hollow notification. Since he is the only one nearby, he runs off to fight the hollow, leaving Karin and her friends behind as they told him that they will be practicing their soccer at the park every day.
The next day, Toshiro did not come for their practice. Karin told her friends that she is going to look for Toshiro. Later, in that evening, Karin found Toshiro in the same spot where she and her friends met him. When Karin was talking to Toshiro, she asked him why he had always came here. He explained the spot is the best place he can find to view the sky. Toshiro got another Hollow notification and attempted to run off, Karin stops him and telling him not to go that way because she sensed something bad. Then, someone has defeated the Hollow, making it unnecessary for Toshiro to go. When Toshiro was about to leave, Karin tries to get Toshiro to come practice with her friends but he does not give her a straight answer.
The next day, Toshiro can be seen sitting on a roof top, watching Karin and her friends practicing for the match. Rangiku suddenly shown up and began teasing Toshiro that he likes Karin. Toshiro then left angrily.
When the day of the match arrives, Toshiro did not show up. Karin and her friends have to play soccer with the middle schoolers by themselves but in the opening play, one of the middle schoolers injured Karin's leg. The middle schoolers had scored four goals while Karin's team had gotten none. Toshiro shows up then. Karin, who was happy to see Toshiro, goes to tells him that he is late. Toshiro tried to tell Karin that he is not here to play soccer but he changed his mind after seeing her injured. With Toshiro's skills, the team got tied with the middle schoolers and when the game was about to be over, Toshiro let Karin score the winning goal which led the team to victory! Karin then thanked Toshiro as he told her that it was her who scored the winning goal.
When Toshiro tried to talk with Karin about something, a hollow appeared. Karin was surprised that Toshiro can see the Hollow also, and is unwilling to run away when Toshiro told her to. The reason why was because she wanted to save her unconscious friends. When the Hollow tried to smash Karin with it's mighty fist, Toshiro, who was in his shinigami form, saved her. Using Hyourinmaru to defeat the Hollow, he slices it in half before it can use it's Cero. Karin watched the entire thing in amazement of how strong Toshiro is.
Once the battle had ended, Toshiro reached out his hand to help Karin stand up. Since she just saw Toshiro is a Shinigami too, she asked him if he knows where Ichigo is. Shocked to find out that Karin is Ichigo's younger sister, he tells her that he doesn't know Ichigo's whereabouts. This upseted Karin at first, but Toshiro cheered her up by saying that Ichigo is trying to becoming stronger, just like she is, and he also told her not to worry, because Ichigo is her big brother after all. Karin then smiles as she wipes away her tears and says that Toshiro is right. When Rangiku shown up, Karin, who had just met Rangiku, is impressed that Toshiro has a captain even though he is just a elementary student. This angerd Toshiro and he yelled angrily that he is not an elementary student.
Toshiro Hitsugaya's HolidayEdit
In episode 316, Toshiro is taking a leave and he can be seen in the Human World, playing soccer with Karin and her team. After the match, Karin thanks Toshiro and asks how long he will be around for. Toshiro refuses to answer her question and when he asks her how long she is planning to follow him, they were approached by Haru, an old lady. At Haru's home, Toshiro tells Karin that he first met Haru when he was stationed in the Human World and explain that Haru can sees spirits, just like her, which prompting her to note that there are a lot of spirits around the house.
When they were talking, Karin saw Yosuke, a Plus spirit as Haru notes that Yosuke has been staying there for a while and asks him to say hello to Tōshirō and Karin. When Karin asks what is keeping Yosuke from resting in peace, Haru says that he wants to see snow and reveals that he died while on his way to go skiing with his family and never got to see snow for the first time.
As they leave Haru's home, while walking, Karin ask Toshiro if it is alright to leave Yosuke the way he is as he will turn into a Hollow. Toshiro then tells Karin about the time when his first posting to the Human World and about Haru and Yosuke. After the conversation, Karin invites Toshiro to stay at her house since he is going to be in the Human World for a while. When they reach home, Yuzu was excited, thinking Karin brought home a boyfriend and she begins to tease both of them. Seeing Yuzu keep on teasing, Karin ask her brother, Ichigo, to say something. Ichigo asks Toshiro what does he think he is playing at, which annoyed Toshiro as he yelled at Ichigo that he has no idea what he is talking about. Later, at Ichigo's room, Ichigo warns Toshiro not to place Karin in any danger.
The next day, Toshiro and Karin goes to Haru's home again. When they reach there, Haru greets them and says to Toshiro that he have brought his girlfriend with him again. When Toshiro went into the house, he gives Yosuke a small ice figure he made using his zanpakuto. Wondering where he get the ice figure, Karin ask Toshiro as he explain about his zanpakuto is an ice-snow type and he can manipulate ice and snow whenever he wants. Later, Toshiro notes that it is unusual that Yosuke has not become a Hollow yet. Karin then finds Haru collapsed on the floor. Toshiro notices that her Reiatsu is weakening and realizes that she had been using her power to stop Yosuke from becoming a Hollow.
Yosuke finally transforms into a Hollow, as Haru is too weak to prevent it. Toshiro tells Karin to look after Haru while he goes in search of Yosuke. However, Yosuke grabs Haru and was about to attacks Karin but she was saved by Toshiro. When Toshiro tries to attack the Hollow, Karin asks him if there is anything he can do to save Yosuke as he replies that there is not. Karin tells Yosuke to hold on a little longer so that he can see snow as she rushes toward him. Toshiro then stop Karin and protect her but Yosuke suddenly stopped as he wonders what happen. Haru uses her power to stop Yosuke and apologizes to him as Toshiro defeats him. Yosuke returns to his Plus form long enough to see it begin to snow.
When they were about leave, Haru apologizes to Toshiro for causing him trouble, but he denies it was her fault. As they walk, Karin wonders and asks Toshiro was it really Haru that make Yosuke stopped moving or was it he battling inside himself. Toshiro did not answer and tells Karin that he is going home since he has done what he came for. Karin smiles and tells him to come over again sometimes as she leaves. Toshiro then notes that he has some leave days remaining and decides to visit his own grandmother.
In the preview, after episode 316, Yuzu asks Ichigo if Karin is going on a date. Ichigo explains to Yuzu that Karin and Toshiro are not going out. Yuzu then replies that they are going out every day and Karin had never liked anyone like that before, which made Ichigo speechless. Yuzu continued saying that maybe they are going to get married when they grow up, as she is excited while Ichigo is still speechless.
"Are you alright?" - Toshiro to Karin in episode 132.