What is the fine-grained topic of the following text: While their prices are already low for what they sell, they are currently hosting a special sale as thanks to their customers, called “KAME-KICHI’s Ongaeshi Sale,” named after a Japanese folk tale “Tsuru no Ongaeshi” about a crane repaying a favor to a man! Only return the topic.
KAME-KICHI's Ongaeshi Sale