The summoning spell was recited incorrectly.
The one who stepped out of the light was not my servant, but the Hero King Gilgamesh. He recognized me as his servant, and the command spell in my hand... Was completely useless.
From then on, my summer vacation became: being used as a servant by the King of Heroes, being chased by my sworn enemy, being guarded by a mysterious servant - and not even a single stroke of my summer homework was done.
This is probably the most outrageous Holy Grail War. And I may be the unluckiest "Master".
Intention: None