Short answers, pulled from the story.
Daisuke Watanabe is a Japanese video game writer born in 1974 and employed by Square Enix. He is known for his scenario writing work on the Final Fantasy and Kingdom Hearts series, with credits including Final Fantasy X, Final Fantasy XII, Final Fantasy XIII and its sequels, and multiple Kingdom Hearts titles.
Watanabe became interested in writing in junior high school in 1988 after reading the Wizardry novel Tonariawase no Hai to Seishun by Benny Matsuyama. Before joining Square, he wrote manga novelizations.
Watanabe served as lead scenario writer on Final Fantasy XIII (2009), Final Fantasy XIII-2 (2011), and Lightning Returns: Final Fantasy XIII (2013). He joined the project in March 2006, fleshed out the plot from chapter eight onward, wrote the full script, and adjusted character personalities. He also wrote a three-part novella, Final Fantasy XIII Reminiscence: tracer of memories, published in Famitsu.
Hiroshi Minagawa, co-director of Final Fantasy XII, stated that many of Watanabe's story ideas had to be cut so the game could meet its release deadline. The project also lost its original scenario writer, Yasumi Matsuno, who left in August 2005 due to sickness.
Final Fantasy X (2001) was the first Final Fantasy game Watanabe worked on as scenario writer. He was responsible for the dialog in the Zanarkand Ruins, which he almost wrote in a single night.
Watanabe described the Final Fantasy XIII series as an exhausting project with little time to breathe, and said his feelings toward it were "complicated".