Initially, he was a good team player and captain for his high-school team, appearing to be on good terms with some of his teammates. However, due to his fallout with his brother, he has become cold, blunt, and overly serious.
As a young boy, Rin was very innocent and in awe of his brother, Sae, wanting nothing more than to become a cool and strong player like him. He started playing football because his brother told him to, following his orders without question. As they played football together, Rin listened to whatever Sae said and adjusted accordingly. When Sae left for Spain, Rin found football was more difficult without his brother but strived to become just like him and replace him. This is where Rin's core style of play would begin to shift from his instinctive style, to a more logical style. Initially, he was a good team player and captain for his high-school team, appearing to be on good terms with some of his teammates. However, due to his fallout with his brother, he has become cold, blunt, and overly serious. He is entirely focused on soccer, to an almost obsessive degree and is also very egoistic, as he is always putting his goals first over everybody and their motivations. Rin has a lot of pride as a striker, which borders on arrogance, since he frequently describes other people's soccer and way of thinking as "lukewarm" or "mediocre". These mannerisms and behaviors came from his brother; In an attempt to be like his brother, Rin copies his words and embodies his mindset. Rin seems to respect almost nobody. He will only acknowledge your presence if you have a noticeable and annoying ability/influence on the soccer field. He seems to have no friends, only rivals (with only Isagi and Bachira seemingly being on generally even terms with him). By the time of the Japan National Representative match he he is more noticeably talkative with the team, giving instruction on the pitch and conversing with Isagi specifically. Rin commits to a routine of aftercare at the end of each and every day, to improve his physique, and he is often found in the training room doing drills or weights. Despite his arrogance and aloofness, Rin truly lives and breathes soccer, dedicating every waking moment to improving himself. This mentality combined with his personality is what makes him the top candidate for Blue Lock's supposed best striker. Everything Rin does is to enable him to beat his older brother and end the rivalry but after Rin moves past his revenge against his brother and his rivalry with teammates, he reaches a clarity in his decisions. He now aims to free himself from anything that ties him down and establish his own identity as an egoist, without relying on his brother, teammates or rivals. Rin is a surprisingly tall teenager with a slim but powerful build. He is noticeably taller than Yoichi Isagi who is older than him. He has black hair with a bang going across his face more in his right eye than left eye, slim teal eyes, and distinct eyelashes that he shares with his brother Itoshi Sae. As a young boy, Rin looks largely the same, his facial features just become more distinct as he gets older. At Blue Lock, Rin wears the standard issued body suit (black with gray stripes) and tracksuit. During Second Selection, he wore Team Red's #1 jersey and wore Team A's #1 black jersey during the Third Selection.
