Piku is an attempt to do several things at once with a science fiction background, not all of which are completely compatible under normal circumstances. This is an outline of my thoughts in general on the setting.
A Piku Future: Piku is intended to feel like a detailed, thought out manga set in the near future (2122). To that end, some things will remain largely recognizable, because stories in the setting must make sense without a doctorate in cultural evolution. At the same time, there will be just enough strangeness and technology to frame the familiar - a story often has more impact when it is put in an exotic setting.
Bad Science, Good Science: Piku has a number of technologies which defy modern science (gates, g-drives and psi, to name the most obvious), but Piku attempts to be "hard science fiction" within the context of these exceptions, and even these exceptions will have hard numbers attached to them. The idea is that it is a "real world" that simply works differently from our own, rather than the tech being handwaved in with technobabble (although some minimal technobabble is unavoidable).
Anime Physiology & Physics: Piku relies on ordinary world physics and physiology for most purposes. However, the characters are protagonists, and are generally assumed to be *better* than ordinary people. Toward this end, characters may be up to twice as strong and tough as they appear, and start with Base Competency 11.
Psi: Piku psi ranges from vague intuitions to shoving a 10 metric ton truck at 50 kph (30 mph). Psi is quantifiable, and the biological energy spike of an exerting psi is measurable by thermal sensors and TEMPEST technology. Of course, no one knows exactly how psi works, exactly, other than it seems to operate on the level of the more esoteric quantum physics (unavoidable technobabble?).
I would like to thank Matthew Weigel for asking the question, "what would cybernetics be like if there were no neural interface possible?" and forcing me to think about it. Although Piku does have neural interfaces, I think the result has been far more realistic cyberware.
Micro Implants
Micro implants are the most common form of cybernetic technology. These are small tech toys that are inserted into the human flesh to perform some function. They are small enough to insert with a hypodermic needle, and low-power enough that they can run on converted body heat. Most implants can be manufactured with garage tech (although they still take a PhD to design).
on worldwide, and built around Webnet protocols, the identattoo is a tiny database chip and radio transciever. Identattoos are about as privacy-safe as they can be (no continual broadcast, at-need info, etc.), but they function as a kind of global PIN, computer, etc. Most computer interfaces today are actually just dumb terminals of one sort or another for identattoos. Each identattoo has a 12 digit serial number (broken into two six digit bar codes with a break between them). They are so named because most chips have a small tattoo (usually four small dots, a triangle, or something similar) showing the exact location on the body.
Biomonitor - Many professions and hobbies find biomonitors of various sorts useful. The most invasive is the Blood Flow Diagram monitor, which has small chips in every major artery and vein, and tracks blood pressure continuously in all locations. Many biomonitors will also be designed with other implants in mind; for example, a person with asthma could have airflow and fluid detection monitors in the lungs and trachea, connected to pseudogland implants in the arteries.
Psuedogland - This is a chemical producing nanofactory, usually implanted into arteries or one of the other body fluid systems. A single pseudogland can typically produce 10 parts per billion of a drug or other chemical in the bloodstream per second. While this may not seem like a lot, it is usually more than sufficient for most modern drugs, particularly when in combination with ten or or so more of them working together in the same artery. A pseudogland can only produce one chemical.
Tracker - A continuously broadcasting beacon with a range of about 100 meters. Only useful if the tracker is within 100 meters of a Webnet uplink (most of the planet).
Implants
Larger implants are somewhat common, but not nearly as much so as the micro implants. They are larger, and often have to have their own battery power source. If a person has any implants at all, there will also be a "plug" somewhere on the body which is connected to all of them and is used for recharging. This plug is typically a millimeter or so wide and concealed with a flap of restructured flesh.
Lenses - This is a small, transparent disc which replaces the natural ones in the eyes. This is the most common method of fixing poor sight today, but it can also be built with additional functions (infrared-to-visible translation, starlight enhancement and vision magnification are the most common). Lenses are usually low power enough that they can recharge themselves on visible light (with a battery life in absence of light of slightly more than 48 hours).
Internal Satellite Uplink - This is a satellite transceiver implanted into the human body (usually into the bone surface of the skull, beneath the skin). This is not as useful as it once was, because Webnet coverage of the globe is fairly complete, but it might still be good if your boat sinks on the ocean. Essentially, the ISU is capable of low bandwidth communication with any Webnet satellites directly overhead. The batteries will power it for approximately an hour.
Hearing Aid - Most hearing aids today are implanted into the flesh near the inner ear. The actual product is extremely generic (a set of precise, flexible-range speakers and a computer), and must be programmed to compensate for the particular problem. The programming can provide everything from enhancing sound volume to shifting the sonic spectrum (if you are only deaf in certain ranges) to nullifying "noise". One particular "aid" is connected to a shotgun mic, and plays what the mic hears quietly into your inner ear.
Prosthetics
Prosthetics are uncommon, but possible. A prosthetic is a cybernetic REPLACEMENT for a natural human organ or limb, such as a mechanical heart or liver. Virtually anything can be replaced, but body parts that are not normally replaced will often require a custom design.
Prosthetics are usually stitched to the flesh with nanites, and "threads" from the prosthetic usually extend a few centimeters into the surrounding tissues to help prevent infections or "breaking" at the point of contact. In addition, skeletal anchors are usually included for any body part that could conceivably suffer structural stress (a prosthetic arm, for example). The other major technology used in most prosthetics is the neural circuitry, microcircuits that can communicate with individual neurons and function as the interface between man and machine.
Since clone tissues can be swiftly grown and reconstructed into the human body, prosthetics are generally considered the cheap alternative for repairing a lost organ. Even in cases where there is a genetic problem, biological medicine can usually fix it better. Replacing a full limb or complex organ (an arm or eye, for example) is extremely difficult with modern medicine, however, and this is usually the only time that prosthetics become the only alternative.
Prosthetics function identically to the real thing (even matching weight, look and feel). Prosthetic limbs can be built stronger and tougher than their human counterparts, and more readily take very large implants.
Getting a prosthetic, regardless, involves the removal of the part it is replacing. Usually, this is accidental, and quite traumatic. People with prosthetics usually have the same problems as real world accident victims (feelings of inadequacy, ghost sensations, loss trauma). Getting a prosthetic without a terrible accident is generally more difficult, as most doctors are a bit leery of deliberately chopping off a healthy limb, and the subject still suffers the physical and emotional trauma of having a healthy limb or organ forcibly removed.
Body Mods
Some of these actually qualify as implants, but they are more subtly so. Body mods have more general acceptance that prosthetics, but are still seen as distinctly odd.
Tissue Restructuring - Tissue can be swiftly cloned and used as construction material in the human body it originated from, allowing rather amazing plastic surgery. Bones and cartilage can be reshaped, muscles bulked up (or slimmed down without neural loss), organs strengthened (or replaced if failing), and more. With the current state of neurology, even new limbs can be grafted on and connected to the central nervous system, although using them requires months of physical therapy.
Tissue Adaptation - The twin sister to restructuring, this takes tissues from other hosts and adapts it well enough to the new body that it avoids rejection. Fur, horns, dolphin blubber... you name it, it can probably be made a part of you. Some of the more esoteric items require special pseudogland implants to provide proper nutrients, since your blood won't carry them.