Another storied piece of Tokyo real estate is up for redevelopment. The 5-floor Ebisu Grand Bowl, opened in 1972, closed its doors at the end of March. The 34-lane bowling alley was built on the site of an old saw mill in a prime location next to Ebisu station at the height of the "bowling boom". Demolition will take place over the next six months but no new plans for the site have yet been unveiled. Commercial rents in Tokyo are on their way up again. Mitsubishi Estate's new Shin-Marunouchi will charge 60,000 yen a tsubo which is 20% more than the company's Maru Biru across the street and a level not seen since the bubble burst. At this rate, Tokyo is on course to overtake London as the most expensive city for office space. It is thought that the massive redevelopment of Tokyo is a factor behind the Yamaguchi-gumi's aggressive move into the area. There is evidence that rival Kanto gangs have been tooling up for a possible confrontation to protect their turf.