He was advised by Mitsuhiro to devote himself to appraisal of old writings, he made a decision to do so, and he got an order to change his family name to KOHITSU from Hidetsugu TOYOTOMI.
そして、光広から古筆の鑑定を専業にしてはどうかと勧められ、これをきっかけに話がまとまり、豊臣秀次より古筆の姓を名乗る命を受けた。