Construction of the Tunnel started in August 1998 and digging began in June 1999. The entire project was divided into six sections. It was completed on February 27, 2005 – six and a half years later. It surpassed the Iwate-Ichinohe Tunnel (25.81km) of the same Tohoku Shinkansen railway to become the longest land-based tunnel in the world. However, about two months later, Lotschberg Base Tunnel (about 34.6km) in Switzerland finished construction on April 28, 2005, forcing Hakkoda to give up its title of the longest land-based tunnel in the world.