Kagome is an ordinary modern schoolgirl living an ordinary life. Who would have thought the dried-up old well on the site of her family's shrine would be a gateway to Japan's ancient past? Drawn through the gate against her will, Kagome finds herself battling demons for control of what she thought was a worthless trinket but is actually a powerful magical gem, the Shikon Jewel! Together with an unlikely ally, the half demon Inuyasha, Kagome begins a quest to recover the shards of the Shikon Jewe...
This is the beginning of the 泊霊山 arc, which is probably my favorite arc besides the very beginning of the story. It adds a lot of interesting mystery, and you really get to start seeing the results of various character's growth over the next few volumes. The 七人隊 really add a lot as antagonists as well. I especially enjoy 蛇骨 and his creepy obsession with Inuyasha.
Also the anime adopted this arc really well! So if you like it, it's probably worth watching that as well.