In the Garden of Words, the main characters which include Takao is a high school student who is just a 15 years old boy whereas another main character Yukari Yukino is a 27 years old mysterious woman and the story of Garden of Words explores how Takao and Yukari developed a beautiful relationship and feelings for each other.
So, the age gap between Takao and Yukari Yukino in the Garden of Words is 12 years.
