The KOHITSU family transmitted the secrets of the art of appraisal of old writings from father to only one child until Ryoshin of the 13th generation and were engaged in the appraisal until the Pacific War.
古筆家は安土桃山時代以降、連綿と一子相伝し、第13代了信に至り、太平洋戦争の頃まで古筆の鑑定に携わっていた。