I Am an Alien, Part 1 (ぼくは宇宙人 その① Boku wa Uchūjin Sono 1), originally I Am an Alien! (わたしは宇宙人！ Watashi wa Uchūjin!) in the WSJ release, is the three hundred seventy-eighth chapter of the JoJo's Bizarre Adventure manga. It is also the one hundred thirteenth chapter of Diamond Is Unbreakable.
Josuke and Okuyasu walk together while Josuke laments that his mother froze his bank account and cut off his allowance for the summer. Suddenly, Okuyasu sees a crop circle in a nearby field. Amazed by this discovery, Okuyasu is overjoyed but Josuke notices someone with a school uniform lying in the circle.
Approaching to investigate, they see that the man in question is a long haired teenager with their uniform, but whom they don't recognize. The teenager then abruptly stands up and asks Josuke if he is on Earth. Josuke and Okuyasu takes it as a hilarious prank and laugh more and more as the long haired guy continues to act strangely. Josuke hands the guy a box of tissues to wipe the blood off his neck, assuming it was fake blood for the prank.
However, when the guy casually eats the tissues, Josuke and Okuyasu stop laughing at the definitely strange behavior and carry on to their destination, where they are followed by the strange man. Okuyasu, seeing that the ice cream shop is closed, laments his misfortune; it is at this moment that the long haired man then gives the pair two ice cream cones from his bag as a token of appreciation for the tissues, startling them as to how the ice cream is still cold.