Japanese Stocks Post Gains on Weak Yen, N225 Futures at 17,900

* Nikkei 225 Stock Average: +109.52 (+0.62%) to 17,842.29
* Nikkei 225 futures Osaka: +170 (+1.0%) to 17,900
* TOPIX: +10.72 (+0.61%) to 1,756.64; Advancers 1,217 x decliners 372 (unchanged 143); new highs 39 x new lows 27; 28 of 33 sectors posted gains
* Jasdaq: +1.53 (+1.92%) to 81.09