DISCLAIMER: This picture was NOT DRAWN BY ME. It was purchased as a commission from the fantabulous Waltz.
As mentioned previously, Minagiru can 'bulk up' by gulping air, inflating his body to present a more intimidating physique, as well as augmenting his strength via some incomprehensible process I never bothered to work out. >>
Here we see Minagiru doing what he does best - getting HUGE. He doesn't normally get this large unless he REALLY feels like showing off - due, in no small part, to the destructive effect such growth-spurts have on his clothes. Remaining this swollen for extended periods can also be a bit taxing, and the bigger he gets, the greater the strain (though frequent practice can gradually improve his capacity, allowing him to reach progressively larger sizes more easily). He can keep himself at this particular size for about 30 to 45 minutes if he has a mind to. At twice this size, he can last for only 5 or 10 minutes, tops. At three times this size (his absolute limit, currently) he'll last for only a few seconds before the pressure becomes too much for him to contain, forcing him to deflate.
Despite the impressive display he's putting on here, Minagiru actually has slightly less control over his ability to inflate than his sister, Isamu, with his 'growth spurts' being limited almost exclusively to his muscles (though he can balloon his gut to a fair size if he strains hard enough). Furthermore, his capacity for air is significantly less impressive than his twin's, to the degree that - even when puffed up to his absolute limit - he can achieve only about one third of Isamu's maximum size. He has long since given up trying to compete with her - no matter how much she tries to goad him into it - though he secretly hopes that he will someday be good enough to at least keep pace with his 'big' sis.
I have to wonder what triggered this little 'blow up'. Minagiru's normally fairly reserved unless his work requires him to put on a display (though he does enjoy the feeling of puffing up). Perhaps he's off work and goofing around, or perhaps some pretty young lass is flirting with him. In either case, he doesn't seem overly concerned by the fact that his little display is bursting his clothing to shreds. He must buy them in bulk...