Hijirikawa is a tall, young man with neatly cut, straight, dark blue hair and bright violet eyes in the game (they are blue in the anime). He has a small beauty mark under his right eye, as well as pale skin and rather long eyelashes. He usually wears his uniform prim and neatly, but wears a dark blue jumper instead of the normal school blazer.
Hijirikawa is usually seen with a rather serious or stoic expression on his face, given his strict upbringing as the heir of the Hijirikawa family. As stated in episode 2 of the second season, on the outside, he appears calm, cool, and collected, but inside 'he hides an enormous feeling on the verge of exploding.'
As the eldest son and heir to the Hijirikawa Group, he was raised in a strict environment because the Group was very important. His way of thinking is a little old-fashioned, and he’s unable to show his real self due to his serious, yet calm nature. He has a soft side to him as well, but he only shows it to Haruka.
He is the eldest son and scion to the Hijirikawa Group and thus was raised strictly. His first encounter with Nanami Haruka was when he was walking during a snowy day, he saw her singing with a group of children at a playground. After that fateful event, Masato decides to enroll in Saotome Academy to pursue a career of being an idol. Though his father refused the idea, he made a promise to only attend the academy for one year. After that one year, he must take over the family's business.
Given names in the Hijirikawa family seem to follow a tradition where the Japanese character for genuine (真) is always present.
His father is named Masaomi (真臣), while his sister is named Mai (真衣).
The characters that form his family name are 聖 (holy) and 川 (river).
His younger sister, Hijirikawa Mai, is only mentioned in the games so far.
He grew up in an all-boys' school.
He prefers winter (cold months) over summer (warm months), not only because it was the season he was born in, but he finds watching snow strange and calming. Also, a lot of precious memories had been made during that season.
He is originally from Kyoto.
He and Tokiya are hosts of the travel program, “Onkochishin Futatabi” (Learning From the Past Once More). In the program, he is the professional eater of the pair as Tokiya is a picky eater.
The program is a travel show where the hosts travel around the country trying the local delicacies.
He got scolded by Ranmaru for studying to 'feel rock' when he was working on Ranmaru's feature TV series, "Rockin’ Scene."
He enjoys hot springs and bath times.
He is generally the source of laughter and recording delays during filming because if he trips, Masato would respond with, "I am in your debt," if he is caught by someone.
He is terrified of bugs but refuses to admit it.
He is incredibly intimidated by his father, and switches to using 'watashi' (a more polite way of introducing self) instead of 'ore' (a more casual way of introducing self) when speaking to his father.
His sister was born when he was 11 years old.
He learned how to talk to girls by taking extensive notes from books he read.
He is well liked by his family's servants.
He took up housekeeping/cooking and sewing at 13 to help his frail mother.
He considers himself to have relatively bad luck.
He likes to make things for Mai like embroidering bunnies and puppies on handkerchiefs for her.