That said, we still have to watch out for upcoming news impacting Yen. Also as Yen is seen as a safe haven, any unexpected calamity will strengthen it. Stop loss is thus placed a few pips below the close of the recent lows and take profit placed at Friday's high with a healthy 1:2 risk:reward.
For the more conservative ones stop loss can be placed at 103.50 in confluence with giving a 1:1 risk:reward.
Note: I'm very new to currencies and only got interested in this pair when it broke 104.400. Experience is very limited.
For personal note:
Scenario 1 - Sticking to original trade: up 4%
Scenario 2 - More conservative traders will place SL at 103.520 at previous low: up 2% (as 1:1 rr)
Scenario 3 - Taking half profit and pushing up stop loss after Jap data: up 1%