Koan is credited with the establishment of a private school, Tekijuku, and many Tekijuku graduates including Yukichi FUKUZAWA, Keisuke OTORI, Sanai HASHIMOTO, Masujiro OMURA, Sensai NAGAYO, Tsunetami SANO, Ryoun TAKAMATSU took the lead in building a new society from the end of the Edo Period through the Meiji Restoration.
洪庵の功績として、適塾から福澤諭吉、大鳥圭介、橋本左内、大村益次郎、長与専斎、佐野常民、高松凌雲など幕末から明治維新にかけて活躍した多くの人材を輩出した。