MS Asuka II (飛鳥II) is a cruise ship owned and operated by Nippon Yusen Kaisha. She was originally built by the Mitsubishi Heavy Industries shipyard in Nagasaki, Japan, as Crystal Harmony for Crystal Cruises. In 2006, Crystal Harmony was transferred from the fleet of Crystal Cruises to that of Crystal's parent company, Nippon Yusen Kaisha, and entered service under her current name. As of August 2022, she was the largest cruise ship in Japan.

The Nippon Yusen Kabushiki Kaisha , also known as NYK Line, is a Japanese shipping company. The company headquarters are located in Chiyoda, Tokyo, Japan. It operates a fleet of over 800 ships, which includes container ships, tankers, bulk and woodchip carriers, roll-on/roll-off car carriers, reefer vessels, LNG carriers, and cruise ships. It is a member of the Ocean Network Express and Mitsubishi Group.