Obsessive-Compulsive Disorder.
For some people, the formation of obsessive-compulsive disorder is caused by making a mistake that leaves a strong impression in their minds.
To avoid making the same mistake again, they demand themselves to perform a large number of repetitive actions to prevent the recurrence of the undesirable outcome.
When the light switch is not fully pressed, the light shorts out.
When the door is not closed properly, it remains open.
Between these two scenarios, which one is more likely to trigger the psychological condition of obsessive-compulsive disorder?
The answer is the first scenario.
Because it resulted in the light being damaged and led to negative consequences.
Next time, naturally, they will pay attention to this issue to prevent themselves from making the same mistake in the same place.
Thus, excessive attention transitions into a pathological mentality.
On the other hand, leaving the door open is just leaving the door open. It doesn't cause any negative consequences, at most, a few mosquitoes may enter, but it won't leave a deep impression in one's mind.
But Mrs. Matsushita...
Her actions indirectly caused a life to be lost.
This impact left an incredibly strong mark in her mind, and it manifested in her behavior. When someone asks her for something, she is utterly powerless to refuse.
No matter how much pain and anguish it brings her.
"But perhaps Mrs. Sannitori may also be suffering greatly."
After listening to Mrs. Matsushita's account of her inability to refuse others' requests, Senichi slowly spoke up.
"Huh?"
Mrs. Matsushita looked at Senichi in confusion, her face filled with doubt, unable to understand why he would say such things.
"Mrs. Sannitori didn't present herself as someone greedy? That's what Mrs. Katori said."
Pausing for a moment, Senichi's tone shifted, "If that's the case, the receiving party may also be hurt."
"How... can that be..."
"You... You..."
Upon hearing Senichi's words, Mrs. Matsushita seemed to understand something, trembling and unable to articulate a complete sentence.
"Mrs. Matsushita, because of your previous experiences, you have developed a character of obliging others. But for Mrs. Sannitori, who doesn't know the underlying circumstances, your generosity has caused her great harm to her self-esteem.
Of course, Mrs. Sannitori might have been jealous of you and even developed feelings of inferiority when faced with your generosity, and the result..."
Senichi sighed, "It led to her becoming more greedy, demanding, and displaying an unscrupulous and villainous demeanor."
One side becomes extremely generous because they cannot refuse others, while the other side has a strong sense of self-worth and is unwilling to accept what others offer, viewing it as an "insult."
These two individuals are truly ill-suited for each other.
Thinking back to when they were shopping and the other party asked her for her mother's scarf, she spoke excitedly, "Once I give something to someone, it becomes theirs. What they do with it is their right, that's what I genuinely believe!
But I thought that the things she asked for would be cherished and used by her."
However, the reality was quite different. On the contrary, Sannitori had sold all those items.
Katori's confession and apology shattered her last remaining illusion.
She couldn't tolerate it, especially when it came to her mother's belongings. The scarf was a cherished treasure for her.
So, she went to Sannitori's house afterward.
At that time, Sannitori had a slight cold and was resting on the couch wearing a mask. When she arrived, she expressed her intention, hoping to retrieve the scarf and not pursue the previous items she had given.
However, Sannitori demanded payment to get it back.
Moreover, Sannitori also mocked her with hurtful words, saying how much she disliked a person like her, someone who only lightly appreciated something, and then directly gave her the items.
It seemed like she was showing off to her as if she had bestowed upon her a great favor. That condescending attitude made her extremely displeased, so she continued to demand items from her.
Sannitori's attitude shattered Mrs. Matsushita's last bit of illusion. But she only wanted to retrieve her own scarf, which was her mother's heirloom.
Then, as she pleaded and apologized, she rushed towards Sannitori, intending for her to return the scarf to her.
The two struggled and wrestled their way into the house, and Mrs. Matsushita ultimately overpowered the weak and sick Sannitori, pressing her onto the sofa.
At that time, the other party was wearing a mask and still had the scarf around her neck. Mrs. Matsushita kept pulling the scarf while trying to take it back. By the time she came to her senses, the other party had gone silent.
Afterward, she retrieved the scarf and quickly escaped through the sliding glass door.
"Did you intend to kill her?" Takagi looked at the sobbing Mrs. Matsushita, asking with sympathy.
"I don't know!"
"You don't know?"
"I just... I just felt so angry, found her despicable. I couldn't release the hand I had around her neck." Mrs. Matsushita choked as she spoke.
The two patiently waited for Mrs. Matsushita to adjust her mood. Eventually, they watched as she took the scarf made of gray squirrel fur out of the evidence box.
"Can't you just throw it away?" Senichi asked.
"Isn't that obvious? After all, it's my mother's heirloom."
Mrs. Matsushita handed the scarf to Senichi, laughing at herself. "But even though it's an heirloom, it's just an ordinary item. I've reminded myself not to be too attached to worldly possessions... Otherwise, tragedies will happen... I already knew that, but still..."
"Well then, let's go."
"Okay." Takagi nodded at the words and looked at Mrs. Matsushita. "Can you please get ready?"
"Detective Takagi, let Mrs. Matsushita postpone her surrender for now."
Senichi held the scarf and said something that surprised both of them.
"Huh?" Takagi looked puzzled. "Detective Senichi, what are you talking about?"
They had already caught the culprit, so the normal procedure would be to have her pack up and take her to the police station. But what was the situation now?
"Well, we still need to capture the real culprit." Senichi smiled at their perplexed expressions and said so.
"What!?"
Senichi's words shocked them, even Mrs. Matsushita, who was sobbing beside them, stopped crying and looked at Senichi in confusion.
"Haven't you noticed? If this scarf was the murder weapon, it would be too blunt."
Senichi showed the fur scarf in his hand to Takagi. The fluffy scarf was made of gray squirrel fur and was about six to seven centimeters wide.
"If this was placed over Sannitori's mask, it would temporarily induce shock, that's for sure."
Senichi looked at the scarf, his gaze deep and solemn. "But it is completely inconsistent with the injuries that strangled Sannitori Sanae!"