explanation please?

Okay, let me try and explain this as best as I can... Takako Nozoe was basically predestined to kill from the very start. This might seem like a strange thing, and it is mainly speculation on my part, but after having seen both movies and the Chakushin Ari television drama, there seems to be a common pattern with the heroine ending up as the killer and using a knife. Yumi from the movie ends up giving in to her evil tendencies in the end of the first movie while Ami from the television series is revealed as a blackmailer and killer by the very end of the series. Ami suppresses her memories and passes herself off as her twin sister (whose death Ami was responsible for in part).

Takako here also has a twin whose death she inadvertently lead her to. Takako also admits to hating her sister and wanting her dead at one point in the movie. In the television series, Ami confessed the same.

So, I assumed from the start that Takako would kill at least one person in the end. Takako's main connection to the death calls was her sister who supposedly died by answering the death phone call at Takako's insistence. Because Takako feels guilt for what she did, she is interested in the death calls. So, her sister is more or less a plot point and a bit of character development and foreshadowing. Her sister's murder hints at Takako's hidden evil side.

In the beginning, the murders are thought to be caused by Mimiko. This was just to keep the viewer from automatically believing that Li Li is responsible for all of it. The deaths in Japan and Taiwan that involve the coal are presumed to be Li Li's doing. The deaths involving the red jawbreaker are all Mimiko's doing.

The question of whether Li Li is evil or misunderstood is debatable. Takako's point of view seems to be that Li Li is not evil, but had noticed an endemic that caused the children's emminent deaths. She seemed to believe that the villagers automatically jumped to the conclusion that Li Li was cursing everyone and killed her. When Okudera Kyoko seems to latch onto this explanation, it does make it seem a bit more real. However, Li Li doesn't stop her killing after she has been found and understood, so it can't be assumed that Takako's assumption was right.

Li Li, while certainly not as heartless and evil as Mimiko, is definitely not a misunderstood ghost. She did allow Sakurai Naoto to switch with Okudera and say goodbye to her, but she did not spare him. If Mimiko had been the killer, both Okudera and Sakurai would have died in order.

Now, when Takako's in the mine shaft, she sees a girl and "faints". The truth is she is stabbed by Mimiko, but as she dies, she is finally reunited with her twin and tries to attone for her part in her twin's death. Takako's spirit returns to Yu Ting with Mimiko in tow. While Takako is unaware of Mimiko's presence at the time, Yu Ting is not so lucky. I do think that Takako was the one who killed Yu Ting in the end and that it was not due to Mimiko possessing her (although this is debatable and you're welcome to think otherwise). Takako buries the murder in her subconscious and so we are left unaware of what really happened.

In the end when Takako finds the tape, we finally see the truth. Both Takako and Mimiko are on the tape, but it's obvious that Takako is the one who kills Yu Ting. I think like Takanaga Yumi from the first movie, Takako gives in to her evil side here and willingly does what Mimiko wants. When Takako spits out the red jawbreaker and recalls her own death in the cave, it's revealed that her murderer was Mimiko. Then she recalls killing Yu Ting.

So basically, the death phone calls are a combination effort apparently. Both Mimiko and Li Li kill and use the phone calls to confuse and predict the deaths. In the end, Takako's spirit also becomes a killer and the only living one left is Kyoko.

Miike had nothing to do with this film...