Metatron Space Corporation opens an interstellar travel route through 7 planets for their cruise entertainment project. Arethusa Interstellar Cruise Port is the one on Planet Arethusa-Ⅰ. It is also a resort on this planet. The cruise stands behind the front hall as a part of the whole architecture, which becomes the most attractive feature of Arethusa Port. The other 6 ports are Hephaestus Ⅲ, Apollo VI, Diana V, Aeolus C, Gaia Ⅱ and Satyr Ⅱ.