Note: As this is a later volume in an ongoing mystery/drama series, there may be mild spoilers for previous books below.
By Volume 9, Seigi has transitioned from a wide-eyed college student to a working adult with established competence. In this volume, Seigi’s emotional intelligence matures. He stops looking at Richard as merely a mysterious figure to be admired and starts viewing him as a partner to be supported. He begins to understand that his "ordinariness" is not a weakness but the very thing that grounds Richard. the case files of jeweler richard vol 9
If you have only watched the anime (which covers parts of Vol 1-3), will feel like a different genre. The "case of the week" structure is abandoned for a serialized, two-part emotional siege. Note: As this is a later volume in