Oedo Kagaku Sosa Hatchobori No Oyu [7] (Takarajimasha Bunko C Ya 6-7 Kono Miss Taisho)

[Machine Translation] A strange incident of koban being thrown into a poor tenement house has the ten-tenant female boss, Oyu, and a contemporary, Yuka Sekiguchi, wondering if it was the work of the famous rat boy. Oyu and her friends were privately consulted by the Hatamoto's official. They were told that bandits had invaded the mansion and stolen 20 ryo of gold and a Wakizashi, a sword known as the "Chiko Muramasa" (a mystical sword). Udagawa of the scientific analysis lab also arrives in Edo, and Oyu begins to pursue the identity of the rat boy and the whereabouts of Muramasa...

貧乏長屋に小判が投げ込まれるという奇妙な事件に、十手持ちの女親分・おゆうこと現代人の関口優佳は、かの有名な鼠小僧の仕業かと色めき立つ。そんな折、おゆうたちは旗本の御用人から内々に相談を持ち掛けられた。屋敷に侵入した賊に、金二十両と脇差―かの妖刀・千子村正を盗まれたという。科学分析ラボの宇田川も江戸にやってきて、おゆうは鼠小僧の正体と村正の行方を追い始めるが...。