If you're looking for manga similar to Digimon Tamers, you might like these titles.
Yun Ling was invited to attend the public beta test of “Apocalypse Calamity.” In the end, she successfully survived a hundred days, and obtained the “Lord Token”, “Life Skill Level Retention” and “S Rank Skill” as rewards. The beta ended, and she waited with anticipation for the opening of the game. But then the world became the game.
Growing up with eccentric materialist parents who left him in the care of his grandfather for a job overseas, Zhang Heng had learned to adapt and be unfettered by the oddities and challenges in life. But he would soon learn the baffling truth about the world he thought he knew when one day at midnight time froze and he found himself in a world so quiet and still it was deafening. That night, he discovered that he had 24 hours more than everybody else and thus, marked the beginning of his adventures. The mysteries surrounding his newfound ability only deepened when a strange old man claimed to have given Zhang Heng that ‘gift of time’ and recruited the young man to participate in a cryptic ‘life-changing’ game on his behalf. Little did Zhang Heng know that accepting those terms meant embroiling himself in many versions of reality and exposing himself to the hidden secrets of the world—a decision he could never undo.
Seven warriors, including Hoshi Hikaru, protect the earth from alien attacks. Their special move is Miracle Nova!
Strider Hiryu was the youngest Strider to ever reach the rank of "Super-A" grade. He was the greatest Strider the organization has ever produced, but he eventually grew disenchanted with them and retired. An uncollected prologue tells how Hiryu had been forced to kill his sister, Maria, who had inexplicably gone insane. He left the Striders for Mongolia, where he lived in seclusion for some years.
Namiro Itsuki is a giant of a young man whose huge stature has earned him the nickname "Baron." His peaceful everyday life is thrown into disarray when a flying saucer suddenly appears before him and his friend Yoko. As the two try meet with various odd encounters, could it be that the UFO is the one tying all these events together?