From MangaHelpers:

The Black Museum holds criminal memorabilia from the many cases that have been investigated by Scotland Yard. In this fictional re-imagining of the popular legend, a visitor comes to see a piece of particular interest, the leg of Spring-Heeled Jack. When the curator guides him to the piece, he begins to tell his story of the case of Spring-Heeled Jack, which began in the late 1830s.

The earlier adventures of Spring-Heeled Jack involved an eccentric nobleman named Walter, who used his specially made suit to harass women. After an encounter with a very strong-willed woman named Margaret, Walter hung up his Spring-Heeled suit for good. Three years later, Spring-Heeled Jack returns, this time with a penchant for murder. Detective James Rockenfield first suspects Walter, but soon it begins to seem that someone else has taken up the mantle... [tethysdust]