Put all your unit down immediately, those who can transform, into jet, transform them and move them, those who are too slow, put them inside your central ship, and MOVE QUICKLY to the three ally ships, for that they will be underattack very soon. if one of them is destroyed, you will have problems...so dont care of the actual enemy fire, and go go go to the bottom of the map. here, you will have new enemy who will appear, 3 enemy ship who will fire at your allys. use all your strong unit against them, dont care of the red haired girl who fire at your unit, destroy the remaining bebels and Then kill the red haired ugly girl. While fighting against her, DO NOT USE your unit "magic power" (you know those thing that make an upgrade for one turn the aims, fire power and other things...). when you destroyed her robot, SUPRISE: the guy that stole the R-GUN of your blue haired girl (sry i cant read japanese, only chinese so i call them by hair color) will appear with a such ugly thing named R-GUN thingy, and pink colored (what a weird color for a battleunit) will attack you. From here, i'm not really sure, i've never passed this mission yet. since, here's the tip to dont get yourself killed:
-put one of your non-strong unit to get rid of the five missiles that appeared.
-All damaged strong unit, at the repair to the central ship!
-All non damaged unit, go at the boss and wait until the others are repaired!
-do not make too much of direct combat (stuck on the boss) for that the boss direct combat is infinite. try to get ride of all his energy first. yes, the boss auto-repair. it's quite ****. it's energy recovering is 100 per turn, so... get ride of his Energy (try). then get ride of the 45 second attack. NOTE: all his attacks are quite very very long-ranged and hurt alot. After, well i dunno... try to make a mass strike and destroy it dammit...