Something wrong in this puzzle...

Check out the source of the puzzle, shown on the right side after completing it: syougi.qinoa.com/ja/
This is a really old site from back in the day that allowed you to play shogi online.
They also had a large tsume puzzle section, and the way that they "forced" you to solve it as a tsume was to set up the position, surround your king in an unstoppable wall of pawns, and force you to play against their AI. That way if you didn't find the right checkmate, the bot would simply mate you.
The fact that these puzzles are weird is just an artifact of when lishogi imported them en mass back in the day. They're strange, but still valid puzzles.

You can't post in the forums yet. Play some games!