There is a rather delicate transition in this volume regarding Obata-sensei's art.
The initial four volumes had a somewhat cartoony touch to them, which was quite fitting considering that Hikaru and his friends were younger at that time. However, as Hikaru grows and takes his very first steps into the professional world of go by becoming an insei, the line art has undergone a significant transformation. It has become much more refined and adheres much closer to a far more realistic style that the artist is renowned for in his later works. This evolution in the art style not only reflects the growth and development of the main character but also adds a new layer of depth and authenticity to the overall narrative. It allows the readers to better immerse themselves in the story and experience the journey of Hikaru along with him.