Amid the growing expansion of Jiyu Minken Undo (Movement for Liberty and People's Right), Mondo founded Aizu Teisei Party (Aizu Imperialism Party) in the joint name with Isuke SUWA and Soji TATSUNO in June 1882, and contributed to the construction of Sanho Road by Michitsune MISHIMA, Fukushima Kenrei (prefectural governor) at the time, and got involved in the Shimizuya Ryokan Affair.
自由民権運動の高まりの中で、主水は明治15年（1882年）6月、諏訪伊助、辰野宗治と連名で会津帝政党を設立、当時福島県令の三島通庸の三方道路建設に寄与、清水屋旅館事件に関わる。