Karen Kurokawa

Karen Kurokawa (黒川 カレン) is the adoptive mother of Izana Kurokawa and in addition, Emma Sano's biological mother.

Appearance
Karen bears a striking resemblance to her one and only blood-related daughter, Emma. She has long, presumably honey blond locks that reaches down to her chest. Her golden yellow eyes look droopy and lack life, framed by slightly long eyelashes.

On the day when she abandoned Emma, she is shown to be wearing a dark party dress, and a pair of heeled sandals. She is also shown to be holding a purse and wears makeup. This shows how she must be so jovial after the responsibility for raising Emma is taken from her hands.

When Izana searched and confronted her inside of a casino building, Karen is shown to be playing pachinko, lacking makeup, and wears a plain black shirt. She is also shown having a nonchalant expression on her face and is shown smoking a cigarette.

Personality
Karen is not a good mother, even to her own biological daughter. She chose to give Izana up for adoption and sent him to an orphanage just because he isn't blood-related to her, and instead was the product of her ex-husband's affair. She can put on a deceptive caring facade as shown when he told Izana that he's going to a "school", which really meant she's leaving him for adoption. When Izana is then about to leave with the orphanage workers and is bidding goodbye to Emma, Karen watches on from the balcony with no emotion, smoking a cigarette.

This treatment also extends to her own young daughter, Emma. She didn't hesitate to leave her at the hands of Mansaku Sano when the chance presented itself. It is also implied that she is neglectful of the siblings when they are still at her hands, showing how unfit she is to be a parent, when clearly, she doesn't seem cut out for that responsibility.

Whne confronted by Izana at a casino, Karen is blunt, harsh, and cruel with her words, not hesitating to use crude words such as "b*tch" when describing Izana's biological mother. She doesn't sugarcoat either, saying that Izana is not her son without any remorse. This impacted Izana's mental health greatly, which is the cause of his meltdown when meeting Shin later that day.

Emma Sano
Karen never held any love towards her biological daughter, Emma. As shown when she never hesitated to abandon the young girl at the hands of her half-grandfather. She never even visited her once and is subsequently not present at her own daughter's funeral, showing how she never loved any of her kids, be it blood-related or not.

Izana Kurokawa
If her treatment is bad to Emma, then what she did to Izana is worse. Having been saddled with the task to raise a product of her ex-husband's affair, Karen may have definitely held resentment towards him, and with the aforementioned ex-husband deceased, this resentment also applied to Izana, who is never aware of the circumstances of his birth at the moment. Karen never thought twice about giving him up for adoption, and when confronted years later for answers, coldly told the then pre-teen youth the truth, along with the words, "You're not my son", which clearly indicated her lack of love towards him, which may also apply at Emma. She never attended Izana's funeral as well.

Etymology

 * Her surname, Kurokawa, literally reads "black river", having been composed with the kanji for "black"(黒)(kuro) and "river"(川)(kawa).
 * Her given name is written in katakana, so it doesn't hold any particular meaning, but it is notable that it's an American name.