Masaji is a supporting character in the story Sukimasuki. He is a second-year university student in the evening architecture department, attending the same classes as the protagonist Heisaku. By day, Masaji works as a carpenter, and he is often seen in work clothes rather than casual attire. He has a tall, imposing build and a stern-looking face that can make him appear intimidating at first glance. However, this appearance belies a genuinely kind and dependable nature. Masaji is known for being helpful and looking out for others; he frequently checks on Heisaku and is well liked by the residents of his apartment building, where he has earned a reputation as a reliable neighbor. His motivation seems rooted in a natural sense of responsibility and a desire to support those around him, especially his friends. Masaji's key relationship is with Heisaku, whom he treats with a protective, almost big-brotherly attitude. He also interacts with other classmates and neighbors, maintaining an approachable presence despite his rough exterior. Masaji does not undergo a dramatic character arc but instead serves as a steady, grounding figure within the group. His notable abilities include his carpentry skills, physical strength, and the practical know-how that comes from his manual labor background. He is not involved in the central romantic voyeurism plot but provides a contrasting, down-to-earth perspective among the more eccentric characters.