Nisekoi second season has a ":" in the name like "Nisekoi:". What is the meaning of that colon?
It's become something of a pattern that anime series will have some kind of notation to indicate sequel seasons. Obviously "Season 2" or variations thereof happen a lot (e.g. "Shokugeki no Soma The Second Plate"), but several shows add a small extra detail to the title instead. Besides Nisekoi:, here are a few:
- Working!! became Working'!! became Working!!!
- K-On! became K-On!!
- Gintama became Gintama' became Gintama° became Gintama.