Giniro no Olynsis: Tokito

The narrative takes place in the year 3567 in a hypothetical future. The entire Earth is encased in a paranormal barrier known as the Olynssis barrier, which distorts space and time. Gardeners, which resemble organic bugs and have taken over the world, want to wipe out all humans in order to "keep and preserve" it. Tokito Aizawa is a member of a team of hunters who use the mecha known as Crawlers to kill Gardeners and sell the remnants. His life does, however, grow more problematic after meeting a girl named Tea who calls him "Koichi" all the time and her enormous machine, Silver.