Volumes 1-11 of "Hatchobori Oyu" by Koji Yamamoto. Set in the Bunsei era of Edo, Oyu lives near Ryogoku Bridge and investigates incidents with her close friend, Doushin Denzaburo... but her true identity is Yuka Sekiguchi, a former office worker and mystery novel enthusiast. She leads a double life, traveling through a time tunnel connected to the house she inherited from her grandmother, spanning two hundred years. Relying on her friend Udagawa, who works at a scientific investigation laboratory, she uses modern science to understand the details of the cases. The question is, how will she convey this information to the people of Edo...? Alternating between the two eras, Oyu gets closer to solving the cases. The premise is incredibly interesting. The love triangle between Denzaburo, and Udagawa, I'm rooting for Udagawa, lol. - Title: Hatchobori Oyu - Author: Koji Yamamoto - Volumes: 1-11 - Publisher: Takarajima Bunko - Genre: Literature/Novel Please understand that these are used items. If you have any questions, please feel free to contact me. We are open to negotiations, including bulk purchases, splitting the set, and price reductions. Please feel free to ask! Thank you for looking. Thank you very much.