Our teacher dedicated his life to the study requiring great pains; as to "Koshi-den", at the end of the Bunka era (1804-1818), he began to write the draft, and by the early Bunsei era (1818-1830), about 12 volumes had been completed; however, by that time, he had also gradually gained an insight into the study and understood the teachings of the master of Suzunoya (Norinaga MOTOORI), then he realized that this world was the product of our great gods of Japan, so he decided to suspend "Koshi-den" temporarily, and first explore and read through all the past annotations of the histories of our country as well as those of India and Europe to use new knowledge to his advantage in writing "Koshi-den"; therefore, since the middle of the Bunsei era, he intensly studied foreign literature and culture mainly, and during a period of over 20 years, he completed almost all his works, which he left for us, including "Sekiken Taiko-den" (Japanese Early History); although he was never satisfied with his works, his students, of course, including myself, with a feeling of gratitude, thought that our master had succeeded in completing most his researches and studies, and were concerned about the delay in completing "Koshi-den" and because of our master's age, we repeatedly begged him to restart the writing, then thankfully at about the 10th year of the Tenpo era (1839), he restarted; however, he was requested to write on linguistic methods so he began to write "Goju Ongi" (Pronunciation and Meaning of 50 Kana) and suspended "Koshi-den" again; after a year, he was banished to Akita Province by order of the former bakufu (Japanese feudal government headed by a shogun), fortunately since Akita was his hometown and there were many relatives of his, besides the former load treated him very kindly, they relieved him off poor living, although under those conditions, he had no time to finish the remaining works; he was always concerned about those unfinished works, and after only a few years, he became sick and regrettably died.
生涯苦心致され候中にも、古史伝は最初文化の末頃より草稿取り掛かり、文政の始め頃に、成文一二巻程は、ざっと稿本成り候ところ、段々見識博くあいなり、殊に故鈴屋大人の御遺教をも相伺れ候て、いよいよ以って、世界悉く我が皇大神達の御鎔造（ツクリカタメ）なされたる事を感得致され候に付、古史伝は先ず差し置き、赤縣州を始め、印度及び西洋の古伝をも悉く皆探索網羅して、其の上にて、充分に古史の註解をと存し込まれ候て、文政の半ば頃より、専ら外国の学に困苦致され、凡そ廿余年も歳月を過ごされ候て、赤縣太古傳を初め、即ち今此れある丈の著述は出来候へ共、中々もって先人の心底に叶ひ候事には此れ無く候へ共、大抵は見当も付き候に依っては、私を始め門人の中の所存にも、段々時節後れ、先人も老年に成られ候に付き、先ず先ず外国の所は大抵にして差し置かれ、古史伝の清撰をしきりて、相願い催促致し候て、天保10年頃より、漸々と其の方にも趣かれ候所、言語規則の書之無きに付き、余儀なく五十音義の撰にかかり、凡そ一ヵ年ほど打ち過ぎられ候所、旧幕府の命に依って秋田へ放逐、尤も同所は本国の事、親族共も少なからず、第一旧君侯より厚く恩遇も之有りて会計の辛苦は薄らぎ候へ共、著述致す可き遑なく、此処両三年心配致され候内に病を発し入幽致され候次第にて残念至極にて御座候。