This website explains the screening process at Narita Airport.

Yes.
The types of baggage passengers carry are divided into two main categories: carry-on baggage that can be brought on board the aircraft and checked baggage that is handed over to the airline, at the check-in counter.
In order to prevent hijackings, security screening is conducted on carry-on baggage to ensure that there are no items that could be used as weapons. In addition, security screening is conducted on checked baggage to ensure that there are no explosives or other items that are prohibited from being transported on the aircraft.
In other words, is knives, air guns, and other such items can be used as weapons, they cannot be brought on board the aircraft. However, they can be placed within checked baggage.

Any item that is prohibited by the Civil Aeronautics Act from being transported, or any kitchen knives, box cutters, or other such items that could be used in a hijacking cannot be brought on board the aircraft. Please place these items in your checked baggage. In addition, restrictions on quantities of liquids apply to passengers boarding international flights. For more information on items that can be placed in your carry-on baggage, please see the following list provided by the Ministry of Land, Infrastructure, Transport and Tourism. If you have further questions, please contact your airline.
(Note: The link is to the Ministry of Land, Infrastructure, Transport and Tourism website.)

Items designated as prohibited by the Civil Aeronautics Act cannot be placed inside checked baggage.
(Examples include toxic gases, flammable gases, flammable liquids, compressed gases.)
Although dry ice, alcoholic liquids, and cigarette lighters fall under the “Prohibition for Carriage of Explosives etc.” in Article 86 of the Civil Aeronautics Act, they are designated as items exempted from the prohibited list in “Appended Notice 18 Determining the Standards for Transport of Explosives via Aircraft. ” For more information, please visit the following link.

No swords (including replicas) or other weapons that could be used in a hijacking can be brought on board the aircraft. Please place them in your checked baggage.
(Note: This includes all air guns, kitchen knives, box cutters, replicas of swords, wooden swords, nunchucks, ninja throwing stars, umbrellas that resemble swords, and other similar items.)

If you are arriving on an international flight and departing on another international flight without entering Japan, restrictions on quantities of liquid will apply. Please note that liquids carried by connecting passengers which exceeds these limits will be confiscated at the connecting screening areas.
If you have a connecting international flight, please purchase duty-free liquids at your final connecting airport. However, please note that this does not apply if you are able to temporarily enter the country and place the liquids in your checked baggage.
The special bags for transporting duty-free liquids that have been adopted by some countries (STEB: Security Tamper Evident Bag) but has not been approved for use in Japan. Please note that items placed in these bags will also be subject to restrictions on quantities of liquids.
[Note: If you have a connection at Narita Airport to a domestic flight within Japan, no restrictions will apply to the quantities of liquids. (Screening of liquids will be conducted.)]

To help facilitate a smoother security screening, please inform the screener if you have a medical certificate or prescription for your medicine. If you do not have such supporting documents, please show your medicine passbook or medicine instruction guide, or inform the screener.
Please note that you can only carry on the amount you will need during the flight. (Medicines and other medical products are exempt from restrictions on quantities of liquids, but must undergo security screening.)

Instead of going through the metal detector, you may choose to receive a pat-down inspection from a screener of the same gender. To facilitate smoother security screening, please show the screener your medical certificate or other supporting documents for your device. You may also inform the screener that you have a metal implant for medical reasons.
(Note: This also applies to passengers using wheelchairs who cannot pass through metal detectors.)

Lighters may be brought on board the aircraft, with a limit of one lighter per passenger. However, some types of lighters, such as turbo lighters, are prohibited. In addition, under no circumstances can lighters be placed inside checked baggage deposited with the airline at the check-in counter.
(Note: Some flights, such as to/from China prohibit lighters in either carry-on or checked baggage. For more information, please contact your airline.)

As is the policy of the Ministry of Land, Infrastructure, Transport and Tourism, we ask that you remove your jacket, coat or other outerwear and place it on a tray before you undergo the screening.

As is the policy of the Ministry of Land, Infrastructure, Transport and Tourism, we ask that you remove any personal computers or other large electronic devices from your carry-on baggage and place them in a separate tray when you undergo your security screening.

Narita International Airport uses the latest high-performance X-ray screening equipment to conduct security screening of checked baggage. Since this device may expose undeveloped film, we recommended that you place film in your carry-on baggage. The X-rays used for carry-on baggage have no effect on film with ISO speeds of up to 1600.

Unfortunately, items that passengers have voluntarily surrendered at the screening area are promptly discarded, so they cannot be returned to passengers. We ask you for your understanding.
The security screening at airports in Japan are conducted under the responsibility of the airlines, in accordance with the Civil Aeronautics Act. For more information on security screening, please directly contact your airline which is responsible for security screening.

The number of screeners assigned to a screening area on a particular day is determined through consultation with the airlines and the security screening companies based on the status of arriving flights on that day. There may be temporary congestion depending on the number of arriving flights. We appreciate your understanding.

The security screening at airports in Japan is conducted under the responsibility of the airlines, in accordance with the Civil Aeronautics Act. Actual screening is carried out by the security screening companies contracted by the airlines. If you would like to express an opinion or report a problem at a screening area, we ask that you directly contact your airline.

Yes.
Restrictions on quantities of liquids do not apply to baby formula or baby food. However, these items will be subject to security screening to ensure safety.
Note: Baby food and formula are exempt from restrictions when the adult passes through the screening area with the child. However, please note that restrictions on quantities of liquids will apply if the adult and child go through the screening area separately, and liquids that are not packed according to regulations will be confiscated.

Some airlines conduct additional security screening just prior to boarding the aircraft. These screenings are conducted independently by the airlines based on their own discretion or on regulations of the destination countries. For more information on security screening, please directly contact your airline which is responsible for the security screening.