The following list are all the inventions, modifications and gadgets featured in Hajimete No Aku. Note that there are no explanations on how most of the items work under deep logical analysis.

Akuno Jiro's Inventions and ModificationsEdit

Device Description Chapters

Confession Seal

A user equipped with this device reveals the innermost voice of the heart, nullifying all forms of lie to reveal all truths in a conversation.


Giant Drill (Not official name)

A huge power-driven mobile drilling machine.It runs by electrical power by connecting the cord to a wall socket. Due to its huge power consumption requirement (in which normal home electrical outlets cannot produce), the machine is rendered unusable.


Modified AirSpace Bag (Not official name)

A modified school bag that can fit all items (even ones larger than the bag itself) without overloading.


Invisible Cream

Applying this cream on skin or clothes enables the user to conceal his physical appearance, rendering him invisible. All other people who uses this cream are able see each other within a similar dimension while physical contact between dimensions, remain the same. After a certain period of time, the cream solidifies which immobilizes the user as the invisibility wears off. The drawback disappears after a few days.


Kill-them Canon

An artificial satellite in space equipped with a targeting laser cannon. The target and its coordinates are manually specified through Akuno's wrist gadget before discharging the laser. It can also be voice operated. The projectile is a thin high speed laser beam capable of boring through thick concrete. With repetitive use, the canon can discharge a devastating rate of fire. It is unspecified if the beams have thermal properties. It has a dangerous auto-lock function in which the canon can auto-fire continuously until the target is destroyed. Manually deactivating the security password is used to override and shutdown the system.

10, 54, 74

Catapult Bed

Modified Bed with a built-in launcher.


Smoke Bomb (Not official name)

A modified smoke grenade.


Ceiling Monitor

A modified monitor ceiling used for surveillance.


Phantoms 100 Dummy entities created by Jiro for her sister when they were young. They were targeted for capture and to be “beaten to a pulp”.


Memory Fire

With the use of a special spray and a medium (in this case, a cam recorder), it can give a physical shape to a person’s recorded memories, giving it an animated holographic appearance. It is possible for the entity to last longer without the medium, if the memory belongs to a person with imposing feelings.


Light Wave Particle Transformation Gun

(a.k.a. Cosplay Gun)

A firearm which operates on a memory stick that contains a record of uniform signatures. When fired at a certain target, the designated outfit (depending on the gun’s affixed setting) is instantly acquired. The temporary uniform lasts within 15 minutes. The early prototype which hasn’t been tested to “civilians” has a side effect of acquiring the personality and traits in congruence to the worn uniform. There is a reset button that withdraws all outfits worn by multiple targets.

17, 56, 60, 65

Strong Robo

A giant robot that can be summoned from a dimensional warp gate. The robot was never seen in full body nor has been put into use.


Imprinting Hormone

A chemical bottle with matching kerchief. A subject who has inhaled the chemical vapor will be rendered unconscious. Once awakened, the subject will be attached to the first target it sees with a strong sense of fondness. The effect can be long lasting and there’s no apparent remedy to reverse the process.


Modified Kyouko's Glasses Kyouko's glasses were modified with Cat ears when worn. There's also a built in radio and tracking function.


Mountain Tractor

A modified tractor. It has mechanical legs similar to a spider instead of wheels. It can plow through mountain paths with ease.


Back Massager

A mechanical humanoid built for massage.


Automatic Pursuit Cap

A light-emitting arrow-like beacon on top of a beanie. When worn, the arrow points and emits a light to the direction of the person whom the user has “affections” with.


Housekeeping Robot (a.k.a. Otsugata)


Mimesis Light

A handy device that resembles a flashlight. It produces a life like movie image. Best used to conceal open areas.


Confidence Booster Z A bottled drink that boost the user’s confidence, reducing the feeling of shyness and shame. Can cause overconfidence with excessive use.


Solar Kitaka Z A small disc which has a figurative shape of the sun. It is an artificial sun that produces heat and light, giving warmth and brightness to dark and cold areas. Prolonged exposure to the heat can be uncomfortable, thus it tampers with one’s inhibitions and drives them to remove his/her clothing to reduce the heat discomfort and gives a tempting pleasure of nakedness. It becomes hot after a period of time, making it impossible to touch.

50, 71

Soul Swap Machine

A lightly built machine operated by switching hosts between their mediums (their bodies). It is possible to switch mediums for more than two subjects due to the machine’s extreme sensitivity.


Affection Checker

A wrist-worn device used to calculate and rank an object (in this case, chocolate) depending on the affection rate of the person whom the item was originated from. The calculated rate of an item is higher if it comes from a close relative or family than those of friends or strangers. It was originally used to determine a suitable host for abduction.


Device Scheduler

A virtual monitor operated over Akuno’s wrist panel. Akuno can perform maintenance on his programmed devices on schedule, such as the Kill-them Canon.


Memory Withdrawal Z A medication in a form of capsules that helps to recall necessary memories that would have been otherwise forgotten. When taken, a virtual cabinet with drawers appears within the person’s mind, with each drawer containing individual memory data that can be easily accessed for instant recall. The memories stored in each drawer can range from simple memorization up to a person’s past experience (whether it’s good or bad), and is arranged from top (present memories) to bottom (past memories).


Contract Enforcement Paper

A modified piece of paper intended to correct an individual’s lifestyle. A subjected host is forcibly prohibited from committing vices written in the contract (in this case, bad habits). Should the contract be violated, a floating metallic sphere that keenly monitors the subject, releases electrical charges against the host.


Adjustable Dumbell

(Not official name)

A dumbbell in which the weight can be variably adjusted up to 1 ton.


Water Punching Bag

(Not official name)

A punching bag filled with water to prevent hand injury when training.


Nail Sengel

A nail sample added to a concoction mixed by a blender. Ingesting the potion grants the user to acquire the physical traits of the individual which the sample was obtained from. If the individual’s strong persona overpowers the host, it would cause the user an undesirable actions.


Air Compression Futon Bag

A durable waterproof transparent bag (that resembles an air bed), which uses an air compressor.


Pleasantly Cool Straw Hat

When worn, the temperature will be augmented to the user’s comfortable level.


Sooth Seater (Not official name)

Brings comfort and music to the user.


Obligation Wake-up Alarm

Basically, a bucket of water attached to a hard hat. There’s an alarm meter set to trigger the device to wake the user.


HQ Builder

A tiny robot dressed as a worker capable of erecting an instant functionable headquarters. It is unspecified for how many hours or days could the robot accomplice upon completion of a structure.


Unnecessary Heaven Seal

Converts lies into truths. It’s usage was not specified.


Desk Cleaner

As the name states, it is a gadget which cleans the desktop. It can also remove gum stains.


Human Roach Motel

A portable device that generates a force field with a wide range. It is claimed to be unpenetrable to pass through the barrier.


Giant Daruma

A huge display built by Akuno Jiro for his Election Campaign to be President of the School Council.


Guard Suits

A transformation wrist gadget that equips the user with a power enhancing battle suit armor. Akuno Jiro managed to build the gadget by duplicating the Giga Rangers' transformation technology.

101-110, 119

Fish Trap

A seemingly ordinary fish trap.


Demon Tag Bracelet and Gloves

These were used in the inside campus demon-tag contest after the HS Sanyousai Festival. The bracelet is worn by the participant while the "demon" wears a special glove for tagging the player. If the demon tags the participant from any part of the body, the bracelet will automatically detach from the wrist and the player is eliminated from the game.