There has been much conflict between the races of the 'Humas', the 'Gabranth', and the 'Evila'. To combat the 'Evila' race's Demon King, the kingdom summons five high school students from 21st century Japan who have the power of Heroes.
However, only four out of five of those students had the status title of 'Hero'.
Okamura Hiiro was summoned by accident since he sat near the other four students in class. Unlike them, he did not have the title of a 'Hero' but instead he had the title of 'Word Master' and 'Innocent Bystander'. Seeing through the 'Humas' kingdom's deceit and insanity, Hiiro decides that he has no wish to partake in their selfish war. Leaving the castle, Hiiro decides to join the Adventurer's Guild and does whatever he feels like. Who knows? Maybe there is some merit to being a 'Word Master' and an 'Innocent Bystander'.
My Opinion: The premise is similar to Shield Hero except the main character has the power to cast magic effects by writing them in the air or on surfaces. He advances in level fairly quickly but has interesting adventures. There is also a translated manga version of the story if you’d prefer to read it that way. The story isn’t licensed in English, so can only be found online.