Neptune and Sun are close friendship and teammates. They seem to have known each other for a while as Sun introduces Neptune as his "old friend". Sun is relaxed enough around Neptune to accidentality let slip that Blake is a Faunus but also trusts him to keep it a secret. When introducing Neptune to the rest of Team RWBY, Sun teases him good-naturally by calling him a "nerd" for thinking the library should only be for reading, not playing board games. Neptune fires back that he prefers the term "intellectual".
Sun and Neptune go on to join Team RWBY's investigation into Roman Torchwick's activities with the White Fang. While trying to help the girls fight Torchwick they are knocked off of the highway, leaving Team RWBY to finish the fight. Sun and Neptune then go to a noodle bar and while Neptune worries they should be helping, Sun reassures him that Team RWBY will be fine.
Sun is also familiar with Neptune's crippling fear of water. When Neptune flees the ocean battlefield during the match against Team NDGO, it is Sun who continuously tries to coax him into participating in the battle. Sun is eventually successful in getting him to help win the match.
After the fall of Beacon, Sun follows Blake to Menagerie, leaving Neptune and his team behind. Having spent months in Menagerie, Sun realises that he has been a bad team leader and needs rejoin his friends, just as Blake is rejoining hers. Neptune and the rest of team SSSN meet him at the train station before heading to Vacuo.
Sea Monkey's became popular as soon as Neptune was introduced in Volume 2. It was one of the most popular slash ships for a time. However after Sun left for Menagerie, Neptune was not seen for three volumes and the lack of new canon material made the shipping activity slow down. Fans were excited to hear about a new RWBY novel, Before The Dawn, that would center around Team SSSN's time in Vacuo.
- A tournament fight between Sun and Neptune and Nora and Pyrrha was planned for Volume 3, but was cut for time.
- Sea Monkeys is a ship name that came from Sun and Neptune's voice actors Kerry Shawcross and Michael Jones.
- Story Time — the ship between Sun Wukong, Neptune Vasilias, Scarlet David and Sage Ayana