After dealing with the Fallen Yamabiko and freeing the living people trapped in the Inner World, Kamiyagawa's recent life has become significantly more relaxed.
Even the young co-lord of ghosts and deities needs rest.
These days, his main activities in the Inner World involved leisurely protecting his liver—mainly cleaning up the remaining minor monsters, in addition to exploring the map. When tired, he would go to Takamagahara's Spirit Training Ground and hang there to grind proficiency in the Spirit Control Technique.
Aokihara Forest is too vast; completing the main exploration tasks will probably take quite a bit of time.
Additionally, while carrying out exploration tasks, Kamiya also took Fukitaku and the little old man with him, following the markings on the "Aokigahara Ore Map (Inner World)" in search of ore.