Amnesia in The memorandum of Kyoko Okitegami

The memorandum of Kyoko Okitegami

Welcome class, today’s topic of discussion will be memory loss as it is depicted in the manga, The memorandum of Kyoko Okitegami. The manga is based on a light novel of the same name and was even made into a live action TV drama that had a 10 episode run in 2015. I only stumbled on the translated manga a few days ago on Manga Stream and I found it to be an entertaining read. However that is not the reason for today’s lesson. Amnesia or memory loss is used fairly often in various forms of media to instill a sense of loss, dramatic tension, or to move the story along. What makes its use in The memorandum of Kyoko Okitegami is that this manga uses one of the lesser known forms of amnesia and the only other time I have seen this particular form used was in the movie 50 First Dates.

Kyoko Okitegami
Kyoko Okitegami


The first thing we need to do is take a look at human memory. I will be giving a basic explanation of the three basic types of human memory. I will not be going into detail about how those memories are formed in the various parts of the brain as I feel it is beyond the scope of the discussion at this time. Just to be clear the science of memory is constantly changing, and is quite complex. So I have tried to simplify and smooth things out a bit for the purpose of this lesson.

Memory pathways
Memory pathways

1- Short Term memory or active memory allows a person to hold a limited amount of information for a short period of time. This is thought to be around 7 items, and the duration is about 30 seconds. Interesting fact this is why the first phone numbers were 7 digits long. Working memory is closely associated with short term memory and allows a person to work with the information stored in short term memory. These processes are unaffected in anterograde amnesia.

2-Intermediate memory is a form of memory that lasts for about 2-3 hours, and the theory behind it didn’t really gain any traction until the early 2000s. Also not much is known about it at this time, but it is thought to be an expanded form of working memory.

3- Long term memory is made up of the information the individual stores for the rest of their life. As for how the memories are created and stored involves working memory. The longer the information is stored in working memory the stronger the memory that is created. This explains why the more you work on something the better that you are able to remember it. Sleep is also thought to play a role in this process. Now there are several types of long term memory we will briefly explain.

Creating memories
How to create new memories

3A- Episodic or autobiographical memory, which is the memory of the events in a person’s own life.
3B- Semantic or factual information, which is the ability to learn and recall basic facts. This is typically considered general knowledge distinct from autobiographical information. An example of this type of memory loss would be not knowing who you are, but still being able to name a country’s capital, or where a sports team is located.
3C- Procedural memory is the storage of information that allows a person to perform a particular task, such as riding a bike. It uses a separate pathway distinct pathway to form memories separate from the ones that are used in episodic and semantic memory.


Next up is a look at memory disorders, specifically amnesia or memory loss as it is more commonly called. It is a neurological condition that affects a person’s ability to recall, and/or form memories. There are a number of different types of memory loss that can be distilled down into three basic categories for our purposes. Just to be clear the science of memory is constantly changing, and is quite complex. So I have tried to simplify and smooth things out a bit for the purpose of this lesson.

Types of amnesia

Anterograde- The patient has lost the ability to make new memories. He or she will remember everything prior to the event that causes the memory loss, but will be unable to make new memories. Essentially every day for them is May 28, 2016 if the event happened on May 27, 2016. The causes include certain drugs, viral infections and head trauma. It also happens to be quite rare with its first official case being documented in the 1953 after a patient underwent brain surgery for a seizure disorder.
Retrograde– The patient has lost the ability to recall events from before the event, but can make and remember new memories. This is the cause behind the classic scene of the person waking up and asking who am I some might jokingly call this Jason Bourne syndrome.
Global- A combination of the two previous types where the patient has a lack of memory before the event and has trouble forming new memories. This type of memory loss is typically short term and very rare. It is usually associated with vascular disease in older patients.

Kyoko Okitegami

In the case of Kyoko Okitegami her particular problem is that she never remembers anything from the previous day, meaning that she has no ability to form long term memories.

Spoilers ahead proceed at your own risk.

The manga even goes so far as to have the culprit in the first case attempt to spoil the investigation by drugging Kyoko’s coffee with a sleeping agent in an effort to make her forget the case she is currently working on. The science behind it is actually correct due to the role that sleep plays in moving short term/ working memory into long term memory.

Spoilers over

The only discrepancy I can find is that a person with anterograde amnesia would have problems with forgetfulness beyond the not remembering each day due to intermediate memory only lasting a few hours. This would lead to a person afflicted with anterograde amnesia having trouble recalling things from earlier in the day. The manga has thus far side stepped this due to the cases being solved in an unknown but relatively short window of time that could be within the time frame of intermediate memory.
Due to the fact that I have not seen the live action or read the novel I cannot comment on how or why Kyoko came down with anterograde amnesia. However if I had to guess I would go with a drug overdose with benzodiazepines used to treat insomnia given the value she seems to put on sleep.

Kyoko Okitegami
Kyoko Okitegami

There is not much in the way of treatment for anterograde amnesia and most of the focus is put on rehabilitation which can include labeling items. This is something that Kyoko takes to the extreme in order to function and is also something of a plot point.

Memories of Kyoko Oketiami

Spoilers ahead proceed at your own risk

If I had one major point of contention with how anterograde amnesia is handled in The memorandum of Kyoko Okitegami, it would have to be in the second volume. There is a point where Kyoko mentions having read her current client’s manga from a previous case. There is no mention of when she read the manga, so I have no way of knowing if it was pre or post the onset of her amnesia. Theoretically, if she read them after the onset of her amnesia she shouldn’t be able to remember them.
Now there is one exception to this, and that is procedural memory, since it works on a separate pathway from episodic and semantic memory; it is possible to make new procedural memories even when a person has anterograde amnesia. As such Kyoko could remember reading the manga, and maybe the emotions she felt while reading it, but not any substantive details about it. As such I am willing to give the author the benefit of the doubt in this case due to the complexity of memory and amnesia.

Spoilers over

Final thoughts

In conclusion I think that The memorandum of Kyoko Okitegami, has done a rather good job in its portrayal of anterograde amnesia thus far in the story. I found it refreshing in a way since the vast majority of the time retrograde amnesia is used to drive the story forward or create drama. At only 2 volumes and a monthly publication cycle it will be some time before more information about Kyoko and her condition will be released. If you are interested in reading the manga yourself it can be found here.
Please leave any comments or questions you have in the comments section below.


One thought on “Amnesia in The memorandum of Kyoko Okitegami

  1. Pingback: Anime Science 101- The Promised Neverland

Leave a Reply

Your email address will not be published. Required fields are marked *