The southern section between Shin-Yatsushiro and Kagoshima-Chūō opened in 2004. The extension to Hakata completed the line in 2011. Heading for Nagasaki? The Nishi Kyūshū Shinkansen runs separately from Takeo-Onsen to Nagasaki. From Hakata, Relay Kamome connects across the platform at Takeo-Onsen with Kamome.
At Hakata, do I board the Kagoshima-bound Shinkansen to get to Nagasaki?
For the Relay Kamome connection, board the conventional limited express リレーかもめ at Hakata. At Takeo-Onsen (武雄温泉), cross the platform to かもめ on the Nishi Kyūshū Shinkansen for Nagasaki. The corridor towards Kagoshima-Chūō is the Kyūshū Shinkansen.
The word literally means “new trunk line”. Everyday usage also applies it to the trains. Keeping the line, named service and vehicle separate helps decode a platform sign: they answer different questions about the same journey.