However, the rumor emerged that the shogunate viewed the sale of Kazan's works to support his life as a problem (one theory says this was a scheme attempted by an anti-Kazan group in the Tahara Domain), and since Kazan was afraid it would damage the domain, he killed himself by seppuku in the barn of the Ikenohara residence, having left the farewell words 'Fuchu Fuko Watanabe Nobori' (Disloyal, Unfilial, Watanabe Nobori).
ところが、生活のために絵を売っていたことが幕府で問題視されたとの風聞が立ち（一説には藩内の反崋山派による策動とされている）、藩に迷惑が及ぶことを恐れた崋山は「不忠不孝渡辺登」の絶筆の書を遺して、池ノ原屋敷の納屋にて切腹した。