good news to all the tennen kakutou shoujo chihiro-chan fans it seems that ALL the 6 chapters from de 4th vol were published in young animal arashi, or at least you can find them in this thread.
The chapters are:
-battle 9 (the one that says "happy new year");
-battle 10 (the one in which we can see a new character with some stars on her face);
-battle 11 and 12 (that ones where a new character appears and challenge the entire wrestling club);
-battle 13 (the one in the beach);
-fight 10 (the magic club chapter);
As you can see in this blog:
http://cartoonworld2.blog.fc2.com/blog-entry-1466.html