The kick-off symposium on “Ladder Polymer Science: Innovation through Ladder Bonding” was held at Nagoya University. Dr. Akimitsu Narita of Okinawa Institute of Science and Technology (OIST), who is a collaborative researcher of the group, gave an exciting invited lecture, and Dr. Takashi Hirose (Kyoto University), Dr. Akiko Yagi (Nagoya University), and Dr. Norihito Fukui also attended the symposium. Thank you for your participation.