The last kanji in Hiruma's name is appropriately the one for demon.
Kurita's jersey number - 77
Hiruma's jersey number - 1
Sena's jersey number - 21
At one point during the scene where Kurita explains what the Christmas Bowl is to Sena, Kurita has eyeballs, as opposed to just having pupils.
Kurita often yells "Funnuraba" whenever he blocks. This grunt of his has no particular meaning in Japanese.
This episode name is the same as the first chapter of the manga! There are a lot of episodes like that.
The final kanji in Hiruma's name is the kanji for demon... explains a lot doesn't it.... For the record, his first name is Youichi.
Sena refers to Mamori as Mamori-neechan, literally, Big Sister Mamori. Mamori's a year older than Sena is, and given their past history, it explains him calling her this.
If her name was written with the proper kanji, Mamori's name would have the kanji for "protect."
Pay attention to three boys bullying Sena in this and the following episode, they will play an important role later on for the Deimon team.
Kurita's positions: Center/Defensive Line, usually as a Tackle.
Sena/Eyeshield 21's positions: Halfback and Free Safety.
Hiruma's positions: Quarterback and Strong Safety.
The scenes played during the beginning of the episode are from the game in episode 3.
Opening Theme Song: "Breakthrough" by Coming Century.
Ending Theme Song: "Be Free" by Rikkenzu.
If you pay attention during the scene where Sena sees all the different clubs, you can see Monta in the backgound.
Sena's overprotective friend, Mamori has know Sena since they were small children. Their mothers met at a cooking class.
Hiruma's a gun-otaku, and loves using firearms of various types to emphasis a point. This has been toned down considerably for the anime.
Sena's speed comes from him always being made to be a gofer for his friends in middle school. All that constant running around has made him the speedster he is.
In Japanese, "Kurita" means "chestnut," which would explain why Kurita's head is shaped like one.