Mt. Ege ("Ege-san" in Japanese; alt. 593 m) is located near Hiroshima City, 12.4 km from the atomic bomb memorial dome. The municipal park at the summit, is a popular Hiroshima sightseeing spot and a habitat of Luehdorfia japonica, a butterfly that is a symbol of the concept of "satoyama" (the area between mountain foothills and flat, arable land). In 2004, construction was begun of a digital TV tower at the summit area. At this time, we reviewed the principle habitat of Luehdorfia with a focus on their flight behaviors. We described successive changes related to individual numbers, ovipositions, and flight behaviors during the construction. The food plant, Asarum hexalobum, was transplanted to the area, and advice was offered to those involved with the construction on how to create and/or maintain a good habitat. Although the population of the butterflies temporarily diminished during the construction, its current status indicates a tendency toward recovery. We are planning to produce a unique natural park, in which Luehdorfia can be observed flying amongst the cherry blossoms in the spring.