Shredder and Tang Shen *Spoilers*
In "Tales of the Yokai", was Tang Shen still in love with the Shredder when she was married to Yoshi and had a baby with him? I mean, she was seriously contemplating leaving Yoshi for Saki and for the two of them going to New York with Miwa. She and Saki obviously dated, but apparently broke up because of his temper ("I'm a different man now").
It was also interesting to note how Saki felt very responsible for Tang Shen's safety and how gentle he was with Miwa when she was a baby.
It would be a funny twist if Karai was actually Shredder's child, as it looks like Tang Shen would have cheated on Yoshi with him....