User Recommendations for Gargantia on the Verdurous Planet

The main protagonist in both series are a battle-hardened soldier trained since childhood but are suddenly thrust into a more peaceful way of life far away from the battlefield. Although the story is generally serious, comedic moments can often be found as the protagonist then spends the majority of the time learning and getting accustomed to their new settings with help from other main characters. You can also find a giant mech that acts like more of a partner & friend, having full, idealistic conversations with the main protagonist in both series and sometimes also ends up surprising the protagonist in some situations.

Both anime have a soldier-boy protagonist -- Ledo and Sousuke Sagara are remarkably similar -- and focus on his adaptation to society. Both are considered to be mecha-anime. Both are a mixture of goofy, slice-of-life entertainment and fast-paced action.