Sashikabe

Description
Sashukabe is a hybrid of Sashigane and Nurikabe, in which the cells in a grid are split into either shaded or unshaded.

Rules
The objective is to shade some cells, subject to the following rules:
 * 1) Each island will be part of an L-shaped polyomino exactly 1 cell wide.
 * 2) All shaded cells must form one stream, which is not allowed to contain "pools", i.e. 2x2 areas of shaded cells.
 * 3) Circles show the bend in the island with numbers in some circles showing how many cells make up that polyomino.
 * 4) Arrows are located at either end of the island and point towards the bend in it.

Example
A standard 10x10 sashukabe puzzle and its solution.