Travel back in time with a Feudal Farie Tale, InuYasha!

Four Seasons

Four scene of love and laughter
I'll be alright being alone
Four scene of love and laughter
I'll be alright being alone
Four scene of love and laughter
I'll be alright being alone
Four scene of love and laughter
I will be okay
Aishi aeba wakare yuku
Sonna deai kurikaeshita
Kioku fukaku tesaguride
Amai kage wo motomete wa
I can taste the sweetness of the past
Dokonimo anata wa inai kedo
I'll be alright
Me wo tsubureba soko ni
Kawaranai ai wo... ...I believe
Haru no hikari atsumetara hana sakasete
Natsu wa tsuki ukabu umi de mitsumete
Aki no kaze fuyu no yuki mo sono toiki de
Atatamete hoshii
Four seasons with your love... ...mou ichidou
Negai dake no yakusoku wa
Toki ga tateba iroaseru
Can you feel me underneath the skin?
Annani kasaneta omoi nara
We'll be alright
Shinjite ireba sou
Donna toukutemo... ...stay with me
Haru no hana nemuru yoru ni mukae ni kite
Natsu no sunahama ni MESSEEJI nokoshite
Aki no ame fuyu no namida kazaranu aide
Atatamete hoshii
Four seasons with your love�c �c yume no naka
Nagareru toki wo kokoro ni ari no mama ni
Futari no hibi wa mou sugu omoide
Ai mo yume mo wasure mono itsu no hi demo
Atatamete hoshii
Four seasons with your love... ... mune no oku
Four scene, four four seasons
Four scene, I'll be alright
Four scene, four four seasons
Four scene, stay with me...

Tenseiga

The Tenseiga is wielded by Sesshomaru, who inherited the sword from his father upon his death. The swordsmith Tōtōsai created it along with the Tetsusaiga from the fangs of Sesshomaru's father, who was a daiyōkai (lit. great yōkai) dog demon famous throughout the lands. Totosai jested that its original name was going to be the coffin cheater but called it Tenseiga instead. Tōtōsai claims that only someone who has the heart to cherish others would be able to use it, but confesses that he has actually little clue to the sword's mysterious powers. Sesshomaru, surprisingly, is able to use Tenseiga's abilities. According to Tōtōsai, Tenseiga has chosen Sesshomaru as its master, regardless of whether he had a kind and caring heart and declares that whether it is to prosper or wane is up to Sesshomaru's heart.
Sesshomaru despises the Tenseiga for its lack of destructive power and early in the story would attempt to acquire InuYasha's Tetsusaiga using whatever means he deemed appropriate. Tenseiga has been used sparingly, mostly only when Sesshomaru feels like using its power for his own gains such as reviving the head of the yōkai Goshinki so that his fangs can be used to create the sword Tōkijin; or when the sword compels Sesshomaru to use it for a good cause. One such example was the sword pulsing to tell Sesshomaru to revive Kanta's father, and in so doing, Sesshomaru learns the demon graveyard his father resides in figures into Naraku's plans.
Sesshomaru's human companion, a human girl named Rin, is brought back to life with the Tenseiga after she was killed by the demon wolves of Koga; Jaken, Sesshomaru's assistant, is revived by Tenseiga as well after Kaijinbō cuts him in two halves while under the corruption of the Tōkijin.

Tetsusaiga

The was made from a fang of InuYasha's and Sesshomaru's full-blooded yōkai father. In its "docile" form, the sword looks like an ordinary (and rather battered) katana. The sword is enchanted with a barrier that severely burns any full blooded yōkai who might try to wield it, and will not transform at all unless the wielder has the desire to protect humans (though this requirement is only seen once). In its active state, it transforms into an incredibly large and heavy weapon that somewhat resembles a cross between a traditional ōdachi and a falchion. In this form the tsuba (handguard) changes into fur and the rest of blade resembles a very sharp fang. This fur is supposed to be white, similar to Sesshomaru's mokomoko, since it comes from their father who had silverish white fur. In the anime, however, the coloring for it is inconsistent, sometimes white and sometimes brown. Since Tetsusaiga is a sword designed to protect humans, its attacks are extremely deadly to yōkai in particular. It is said that the Tetsusaiga has the power to slay 100 yōkai in one swing by striking using the Wind Scar technique. One notable example of this ability was the effects of the Wind Scar on Sesshomaru, who has shown incredible resistance towards holy and divine attacks, yet was injured severely by the Wind Scar. Furthermore, Tetsusaiga's Bakuryuha technique can only be performed on a yōkai or something with youki energy. Thus, it can be concluded that Tetsusaiga was created to specifically kill yōkai. Non-yōkai with unusual powers, such as Kikyo or some holy men, can sometimes neutralize the sword or its attacks.
Upon InuYasha's father's death, Myoga acted upon his lord's final instructions and hid Tetsusaiga within the tomb of InuYasha's father. The gateway to the tomb was then hidden inside a black pearl that was somehow cast into InuYasha's eye without his knowledge. Upon receiving Tenseiga after his father's death, Sesshomaru began to seek out the Tetsusaiga, and was enraged to discover that it was enchanted against his ability to master it. He has wielded the Tetsusaiga in brief moments, but the barrier around Tetsusaiga rejects him, severely burning his flesh. It is obvious that InuYasha's father intended this from the beginning, so that the brothers could not duel to the death after he was gone: Tenseiga could not kill the living until Tōtōsai reforged it, and it has protected Sesshomaru from the blows of Tetsusaiga on occasion, although he was still weakened considerably for a time, most likely due to it not protecting him until after he'd already been hit by the brute force of the attack. Tetsusaiga's sheath similarly protects InuYasha from attacks by other yōkai swords.

Akago

Akago is a young infant incarnation, capable of speaking fluently, that Naraku created while in Hakurei-Zan. Akago is the physical life force of Naraku planted within an incarnation, allowing Naraku to withstand otherwise fatal damage. Akago, much like Naraku, has a liking of ordering others around and watching from the background. Akago has the ability to peer into living beings' souls, with which he can manipulate and control by grabbing on to their inner darkness. Due to being created on a holy mountain, Akago can also erect barriers with which he can block and reflect yōkai energy.
Once Naraku receives news of the final shard of the Jewel of Four Souls being in the borderland between the worlds of the living and dead, Akago and Kagura half-kill priests and monks in order to peer into the borderland. This remains unsuccessful until a more powerful priest slices Akago in two during his final seconds of life. Akago's halves are split between Kagura and Kanna, Kanna's half reforming into Akago, while Kagura's half became Hakudōshi. Akago is then placed by Kanna and Kohaku into the care of a daimyō's wife, who Kanna led to believe was her own newborn child, the actual child having been a stillborn child. After Abi-Hime's birds attack the castle and Kohaku kills the daimyō's wife, Akago was taken into hiding again.
After some time, both Akago and Hakudōshi grow tired of being ordered around by Naraku. As Akago is Naraku's life force, becoming independent was all the two needed to do to make Naraku lose all power. Thus, Hakudōshi created Mōryōmaru to protect Akago and be a more powerful body for him. Akago later is merged inside of Mōryōmaru by Kanna to give Mōryōmaru a soul. After Mōryōmaru is merged back into Naraku, however, Akago is as well, thus destroying both of them.

Kagura

Kagura, the wind-witch, is Naraku's second detachment and one of the longest-lasting. She, Kanna, and Hakudōshi are the only three to survive through multiple battles. Kagura is very frequently used to scout unknown territories or to keep and eye on Naraku's enemies and other incarnations, though she fullfils her job very reluctantly.
After her first battle, staged by Naraku to test InuYasha's power, Kagura began to resent Naraku's hold over her and plots secretly to destroy him by aiding Sesshomaru and sometimes InuYasha. Her plans, however, are unsuccessful, as Naraku eventually discovers her secret after she allows Kohaku to escape.
Naraku pretends to be setting Kagura free by returning her heart to her, but then subsequently poisons her. She dies soon after in a field of wildflowers, with Sesshomaru and InuYasha's group looking on. When asked if Kagura was suffering, Sesshomaru replied only that she was smiling. The chapter ends with a frame showing Kagura's white feather floating away and Kagura's "signature" line, "I am the wind, as free as the wind."