lol nah it's kinda... you'd only get it if you saw the series. Sei (the blonde one) is always glomping on yumi (pigtails) which always upsets sachiko (black hair). in this little strip it's like... sachiko is trying to get back at sei by glomping shimako (brown hair) because shimako has a sort of thing with sei.
What I wonder is Yumi have enough strength to punch Sachiko-sama that strong but she can't just get rid of Sei? Or maybe she just pretend that she can't get Sei away??? :P