"I'm going to save Japan with an excavator?"

Sakakibara Hitoshi loves excavators. He even makes life decisions centered around excavators. Excavator――official name is hydraulic shovel. Also known as power shovel or backhoe. However, in the Kansai region, it is often called "yunbo." Such an excavator-loving me was transported back to the Taisho era. There, I meet Lieutenant Kanzaki and work hard toward developing a domestically-produced excavator. As a bonus, Japan also changes along the way. This is alternate history fiction. The first half is an internal affairs section and the second half is a war section.