Captain Grafton is the first captain of the SRF-003 Calnus in the game Star Ocean: The Last Hope. He can be first seen commanding the ship until he leaves after the mission on Aeos to take command of the Exploration Base on Aeos. After he has stepped down as Captain, Edge takes his place.
While commanding the Calnus, the ship, along with the SRF-002 Balena, the SRF-004 Dentdelion, and the SRF-005 Eremia, crashland on the planet Aeos. Unlike the other ships, the Calnus suffers no casualties. However, some of the men are injured, including Grafton, who broke his left arm. After crashlanding, Grafton orders the men to search the area around Calnus, during which they rendezvous with the surviving crew of the Balena and the Dendelion.
Later, he is seen talking with Deputy Director Shimada about the creatures they just encountered, stating that there was no mention of hostile lifeforms in the reports on Aeos and requests assistance from the USTA. Shimada refuses, telling him that they are supposed to get rid of any threats to colonization, revealing that he knew about the creatures on Aeos, but decided to let the SRF deal with the threat. However, he then says that because he does not want his reputation to be ruined for being a "cold-heart superior whose all talk," he had already contacted "them", which surprises Grafton, who, along with the other four captains, knows who "they" are. Afterwards, he tells Edge and Reimi that they have lost contact with the Eremia and orders them to go find what had happened.
While Edge and Reimi are off on their assigned missions, the Eldarian envoys arrive and rendezvous with the extraterrestrial beings. Together, the Earthlings and the Eldarians deploy an advanced prefabricated frontline base and begin work on mutually developing the planet to suit both of their people's needs. After contacting Moonbase and Earth, Grafton becomes quite fond of speaking of his children, and will show photographs of them to any Eldarian he runs into.
After this, Edge and the party travel out into the forest and upon returning reach the Exploration Base which has replaced the original Landing Point. When Edge enters the base, he is told to go and meet Grafton, who has been assigned as the commander of the Exploration Base, and Supreme Commander Gaghan. After learning about what happened to the Eremia, he tells Edge that he, Reimi, and Faize are to continue searching for planets to replace, as well as find out what happened to the SRF-001 Aquila. In addition, he appoints Edge as the new captain of the newly fixed Calnus. He is presumed dead after the party returns to Aeos following the events on Roak and seeing the base destroyed.
- When speaking to one of the Eldarians at the Exploration Base, it is revealed that Grafton has a son back on Earth and that he enjoys showing off pictures of him.
- If speaking to Grafton after the mission to Lemuris, he reveals his prior memories of Edge are likened to an out-of-control freighter, prompting a surprised Faize to ask whether he was really such a handful.