© 2019 Copyright is held by the owner/author(s). Publication rights licensed to ACM. Large-scale natural disasters are a frequent occurrence in Japan. During and after such disasters, numerous messages (i.e., tweets) related to the disaster are posted on Twitter. For recent disasters, such as the 2017 Northern Kyushu Floods in Japan and the 2018 Japan Floods (the July 2018 heavy rain disaster in Japan), victims who needed to be rescued used the hashtag # 救 助 (meaning #Rescue) in the tweets they posted to request a rescue. As only a few studies have investigated the effectiveness of such hashtags, an investigation into the circumstances of the posted tweets with rescue request hashtags needs to be conducted to enable better rescue and relief activities. In this paper, we collect and analyze tweets with rescue request hashtags that were posted during and after the 2018 Japan Floods.