The Japan international became the highest goalscorer from his nation as he broke the 10 goal barrier for the first time in the Premier League.
Mitoma told the club's website: "I felt my condition improved gradually. There were tough periods with the national team schedule too, and I faced a lot of challenges. But I want to use those lessons and apply them next season.
"I believe I can push those numbers higher. At the end of the day, not qualifying for Europe says it all."
On why Brighton fell short in their bid to qualify for European football, Mitoma also said: "Definitely game management. We turned too many winnable matches into draws.
"That was frustrating, but we also had games where we came from behind and made them ours. A lot of 'what ifs' this season, really."
On manager Fabian Hurzeler's first season at Brighton, he added: "He really emphasised collective defending, especially from the front line.
":That was a big focus from the beginning, and he judged players based on how well they executed that. Of course, results matter, but he valued how much we contributed as a team."