The theme songs from the Air visual novel are used for the anime's opening theme, ending theme and soundtrack.
Unlike the first anime, the actual theme songs from the Kanon game are used for the second anime's opening theme, ending theme and soundtrack.
The Futari no Elder visual novel has four theme songs: an opening theme, an ending theme, and two insert songs.
The visual novel has three main theme songs: the opening theme, the ending theme "Farewell song", and as an insert song.
The themes were identified for each open ended question and comments assigned to each theme.
The words of the subjects were utilized as much as possible in the themes for the open ended questions in the written survey (see Table 2 for themes and data examples).
The majority of questions required yes/no responses followed by open ended questions to explore qualitative themes.
It also released two "Expert CDs", which features the radio drama, opening and ending themes and unreleased soundtrack songs.
Notable artists who sang opening and ending themes for the series include Nami Tamaki, who was fourteen years old when the third opening theme was used, and T.M. Revolution, who also provided the voice for the character, Miguel Aiman.
Three compilation albums, Eyeshield 21 Original Soundtrack Sound Field 1, Eyeshield 21 Sound Field Especial, and Eyeshield 21 Song Best, featuring opening and ending themes, insertion songs, and character and team songs were released on August 31, 2005, December 21 , 2005 and March 23 , 2006respectively.
Open ended responses were examined to identify themes, and then individual responses were classified according to these themes.
