Happy New Years Indonesia and China
I went on the hunt for some puzzle genres I had never done for this set. One of the places this regularly leads me is of course Naoki Inaba's site. There seem to have been a few changes to his site. You can now copy all Japanese characters and some of the puzzle types have English translations added to it from the Naoki-Projekt on Logic Masters Deutschland. When I saw this type, I figured it could be a good genre to use the number 2 on. It took a while to get it unique. The opening is a bit standard, but in the end it gets a bit trickier, but there was no better way to force it unique. The name of the genre comes from google translate. It translated the puzzle name as "Santoitchi" but suggested I might mean the Japanese for Sandwich. It might have an alternative meaning but I got persuaded to just name it Sandwich. I have no real clue why it would called this though and I guess I could just stick with Santoitchi, as many Japanese puzzle types keep their original Japanese name.
The puzzle is medium/hard difficulty. There's a logic path to the end, but for a new genre it might be a bit trickier. It might help to try some of Naoki's at first.
2 - Sandwich
Colour some cells black, so that the remaining area can be split up into triminoes. No two black cells can share an edge. Each trimino must contain a number. A number indicates how many black cells share an edge with that trimino.