Castles · 箱入り娘
Daddy’s Dearest.
The Boat castle one move further: the 5h gold slides over to 6h, and the king is shut in a box of gold, silver and bishop.
How it goes together
Build the Boat castle, then slide the gold on 5h one square to the left, to 6h. The king on 7h now has the bishop on 8h on one side and the 6h gold on the other, with the silver on 7i and the gold on 6i below. The 6h gold stands over the 6i gold, the Boat’s loose piece, and guards it; the 6i gold and the 7i silver guard the 6h gold in turn. The Japanese name, hakoiri musume, is a daughter kept at home as if in a box: Katō Jirō gave it for the king sitting as if packed into one. English sources also call it the Girl-in-the-House.
Every Daddy’s Dearest starts as a Boat: the first seven moves below build it, and one gold move makes this castle.
Move by move
Black only, from the start position: the Boat castle’s seven moves, then one more.
Step through the moves, or press play.
Tap a move to jump to it. Arrow keys work once the board has focus.
Eight moves. The last one moves no new piece: the gold the Boat put on 5h steps sideways next to the king, and the right silver and the rook are still free for the attack.
What it is good against
One move. It is firmer than the Boat for the price of a single gold move, and the 6i gold, the Boat’s weak point, now has a gold over it. Shogi Wars calls it surprisingly strong against attacks from the side. ja.wikipedia adds one case: when the static rook swings its rook to the third file to attack the bishop’s head and the silvers are traded, this shape avoids the silver dropped between two golds (割り打ち) that the Boat allows.
Where it breaks
No way out. The king’s road to the right is blocked by his own gold on 6h, so attacks at the edge or on the king’s head are hard to meet. The 7i silver cannot move without opening the box, so unless the castle grows into something else it does little. And ja.wikipedia calls it much weaker than the Left Mino, the other castle that grows out of the Boat.
When to build it
Static rook against ranging rook, when the right silver goes out for a rapid attack (shogi-gym: against the Third or Fourth File Rook, and against a Central Rook when playing second). ja.wikipedia names the right-silver attack with the silver on 4f (４六銀右) against the Fourth File Rook as a typical home, and says it is rarely used once the ranging rook has a High Mino or Silver Crown. It also appears on the way to a Static Rook Anaguma or a Left Mino, while you watch what the opponent does.
Build it at the board.
The app’s lesson walks the king into a Mino one step at a time, and its review names the castle you were building when a game turned.