BUR #24807 has been approved by @nonamethanks.
create implication toushin_toshi_i -> toushin_toshi
create implication toushin_toshi_ii -> toushin_toshi
create implication toushin_toshi_iii -> toushin_toshi
create implication toushin_toshi_girls_gift -> toushin_toshi
Groups all games by series. May also have Girls Gift implicate II, but unsure as the characters have different designs in that game.