Ren Amaki is the Sword Hero, one of the four holy heroes summoned in Melromarc.

Ren comes from an Alternative Japan. In the world he lives in everything is much more advanced and futuristic. In his world, every game in the modern era is run on VRMMO.

One day while on the way home from school, Ren was caught up in a murder case. The murder case was pretty well known around the town he lived in. Ren mentioned how he remembers saving his best friend and how the criminal arrested. Ren didn't go into too much detail after that but started rubbing his side when talking, it was suspected that Ren was probably stabbed on the side of his body during the struggle then later died from blood loss.

Before he knew it he woke up he found himself summoned to another world. The world reminded him a lot of the VRMMO he played in the previous world, Brave Star Online.

Ren is a person who acts cool and tries very hard to portray a loner's image. He runs his party like a guild, only working with the other members when the prey he seeks to kill is too strong for him to hunt alone. His attitude towards his comrades is that weaker members should work to individually increase their powers to catch up to the stronger ones.