Medaka Sexing

[MasterPython]

I picked up these medaka from a local pet store in June and I have not seen eggs yet but the water has only gotten to 25°C in the last week or so. Is the one in the front a male and the one to the right a female?

 

[ruud]

body-wise, looks female-ish
fin-wise, the one in font looks male-ish, the other more female-ish

I'm not good at sexing fish

 

[MasterPython]

I finally found an egg on a mop and there is a cluster hanging on off one fish.