Aigakari System (Double Wing Attack)
When both players extend their Rook's pawn and exchange pawns, the opening is called Aigakari (相掛かり) or Double Wing Attack. There are various forms of Aigakari system.
Koshikake gin (腰掛銀=Sitting Silver) system
Here is an example of the Sitting Silver System
Kusari gama gin (くさり鎌銀=Chained Sickle Silver) System
Here is an example of Kusari gama gin system
Hineri-Bisya (ひねり飛車=Twisting Rook)
This is a Rook twister. The rook will "dance" side ways
Yokofu Dori (横歩取り=Side Pawn Picker)
Ai Yokofu Dori (相横歩取り=Side Pawn Pickers)
This is what happens when both player goes for Yokofu
Ai Yokofu Dori San San Kaku (相横歩取り３三角= Side Pa... 33 Bishop)