Foreshadowing in Bleach.
- In the beginning of the manga, one of Ichigo's first hollow-hunting assignments deals with Orihime and her hollowfied older brother. Ichigo reveals his belief that a big brother is born first to protect the younger siblings that follow. This becomes significant during Ichigo's climactic battle with Byakuya where he berates Byakuya for failing to protect his younger sister Rukia.
- During the Soul Society arc, Rukia, Byakuya, and Ukitake are each struck by the physical and psychological resemblance Ichigo bears to the late Kaien Shiba. A couple hundred chapters later, it's revealed that Isshin, Ichigo's father, was originally a member of the Shiba clan. Ichigo and Kaien look alike because they are first cousins.
- In fact, Byakuya's comment about Ichigo resembling Kaien also foreshadows something else. He tells Rukia at the beginning of the Soul Society arc he understands her desire to protect someone who looks so like a man she misses keenly. It's only at the end of the Soul Society arc that the readers learn that Rukia is the spitting image of Byakuya's late wife Hisana, that he made a solemn deathbed promise to Hisana to protect Rukia, and that he was forced to disregard that promise until her false conviction was resolved.
- Yumichika's true shikai is hinted at in the Soul Society arc when he fights Hisagi, but it takes about 200 chapters to actually see it in action.
- During the fight between Uryuu and Mayuri we see a flashback of Uryuu talking to his father about Ryuuken's rejection of his quincy powers. When challenged, Ryuuken says only "I have no interest. You have no talent." When Ryuuken appears in the arrancar arc, Uryuu is shocked that his father does indeed have quincy powers. Ryuuken points out that he never said he ''lacked'' powers... only that he wasn't interested in using them.
- Uryuu's brief use of Letzt Stil against Mayuri, when he starts absorbing reishi so rapidly that he destroys surrounding buildings. It's the first mention of "reishi enslavement" as a Quincy capability. Fast forward 400 chapters, and the evil Vandenreich has a modified form of Letzt Stil called Vollstandig capable of the same feats but without the one-time-only drawback...
- The manner in which Uryuu performs "reishi enslavement" is comparable to how "Old Man Zangetsu" absorbs Ichigo's hollow spirit into himself, serving as a hint to the true nature of the old man in black.
- In the Soul Society arc when Choujirou is ordered to attack Ichigo, he states the name of his zanpakutou, Goryoumaru. An old-fashioned reading of the kanji for "goryou" is "lightning". Hundreds of chapters later, it's eventually revealed that his bankai gives him the power to control the weather to produce lightning as a weapon. During the zanpakutou arc anime filler, the anime team asked Kubo to design the zanpakutou spirits, so Goryoumaru is actually seen using lightning-based powers, also foreshadowing the eventual reveal.
- At the end of the Soul Society Arc, Ukitake quietly gives Ichigo a badge meant to mark him as a sanctioned substitute Shinigami. Yet, Uryuu thinks something is off about the situation and the Mook guarding Karakura Town doesn't recognise it. The Chekhov's Gun takes a long time to fire: The badge is a spy device and Ichigo is only the second person one to receive one, after Ginjo Kugo.
- Shinji's first appearance in the storyline (his first appearance in the manga is actually on the Chapter 1 cover) has him walking upside down in the sky drinking water as if he were right side up. In his introduction to Ichigo's classmates he mentions backward writing is a particular talent of his. More than 200 chapters later, the reader learns his zanpakuto's ability allows him to flip the perception of its target so all directions are reversed.
- During Aizen's fight with the Gotei captains, Aizen moves extremely slowly while getting beaten by the Captains and being horrified when Hitsugaya stabs him, despite showing no reaction to Yamamoto's attacks earlier. This is because the captains aren't actually fighting him at this point.
- There's a lot of foreshadowing throughout the series of the late revelation that Ichigo is part-quincy and the corollary that his sword's iconic form and "Old Man Zangetsu" are manifestations of his quincy powers, not his shinigami powers; the inner hollow is the manifestation of his shinigami powers.
- More apparent in the anime, but the sheets on Ichigo's bed show a distinct large cross on them, resembling a Quincy cross.
- When Ichigo first escapes the Shattered Shaft, there's a shot/panel of Tessai looking spooked at the sight of Ichigo's zanpakuto. This is never addressed, but it makes sense in the context of the later reveal: Ichigo shouldn't have a zanpakuto at that point because he never got a blank blade to imprint it on. The blade is made from his quincy powers.
- During his fight against Kenpachi, at one point Old Man Zangetsu pulls Ichigo into his inner world. The imagery of this is very similar to the shadow-hiding technique the Vandenreich use. In his inner world, he has to fight a strange lookalike of him for the privilege to wield Zangetsu. The lookalike calls Ichigo "partner" when it arrives and during their fight it berates him for not knowing anything about Zangetsu. This is because the lookalike is his inner hollow, the actual Zangetsu. After the scene ends, back in the outside world Old Man Zangetsu halts the bleeding of the stab wound in Ichigo's chest; after the big reveal hundreds of chapters later, Ichigo muses that this was done using the quincy technique Blut Vene. Later, when Kenpachi flares his reiatsu in preparation for their final clash and it forms a skull behind him, the image in Ichigo's answering flare resembles a hollow mask. The old man has to pull on Ichigo's shinigami power to match Kenpachi.
- When Ichigo asks his inner hollow where Zangetsu is, the hollow repeatedly claims it is Zangetsu. Later in the meeting it explains that it grew stronger than the old man, so whereas before the old man could decide whether to let the hollow manifest, now the hollow was the one in the dominant position. Actually, the Hollow was telling the literal truth the first go-around. He is the real Zangetsu, who's a Hollow because he fused with the hollow White when Ichigo was born. The old man was lying when he called himself Zangetsu.
- When Ichigo uses the Final Getsuga Tenshou, he briefly changes appearance and has an extreme power boost, then loses all of his spiritual power. That's because it's his Letzt Stil, the quincy technique Uryuu uses against Mayuri.
- When Gin battles with Ichigo in the Deicide arc, he finds Ichigo's resolve wanting, and delivers a Breaking Speech, telling him to run away. He then says a line which feeds into Ichigo's despair: "You can sense his power can't you? Do you think you're able to go up against him when your allies can't?" The thing is, no-one including Gin could perceive how powerful Aizen had become due to the Hogyoku except Ichigo. That is the first sign that Ichigo is still on Aizen's level and capable of surpassing him with his own power — which he ultimately does when he masters the Final Getsuga Tenshou. This is because as a natural-born Human-Soul Reaper-Hollow-Quincy hybrid, he already had the innate ability and potential to become a Transcendent Being like Aizen.
- The chapter wherein Uryuu is first properly introduced has a a title page where Ichigo (the shinigami) is right side up and Uryuu (the quincy) is upside down, symbolizing their mirror-image relationship. This recurs on the title page of Chapter 189, wherein both boys are struggling with choices about their powers and their values. This imagery takes on a whole new meaning when the reader learns that the Vandenreich's shadow dimension actually exists underneath Seireitei.
- After Grand Fisher is beaten early in the manga, he is shown being healed and put back together as a more humanoid Hollow. Two arcs later, we learn that he was turned into an Arrancar.
- When Yammy draws his Zanpakuto against Ichigo, Ulquoirra chastises him for needing it to "deal with a runt like him". No other Espada's Zanpakuto releases are ever commented on, or treated like such a big deal. This is because Yammy is actually Espada #0, not #10, meaning he's the strongest member of the group. Only by releasing his Zanpakuto is his true power and rank revealed.
- After being subdued, Ichigo's Inner Hollow warns Ichigo that if he slips up he'll take over completely. When Ulquiorra brings Ichigo to the verge of death, the Inner Hollow consumes Ichigo completely.
- Remember when Uryu told Ice Ringer that Aizen should not fear the Soul Reapers, but the Quincy? And Cirucci's snide remark about how the Quincy were "a sad group of people who were destroyed by the Soul Reapers"? Take one guess as to which group conquered Hueco Mundo eighteen months after Aizen's defeat and then invaded the Soul Society?
- Ginjou describes all Fullbringers as someone whose parents were attacked by a Hollow before they were born, thus giving them "a little Hollow in them". In the next arc, we learn that this is true of Ichigo too, courtesy of a prototype Arrancar that attacked his mother, Masaki, before he was ever even conceived.
- Ichigo's true heritage and the truth about Zangetsu were foreshadowed several times. The Shattered Shaft manifested Shinigami and Hollow forms equally; Zangetsu stopping Ichigo's blood loss against Kenpachi was Quincy "Blut" power; the inner Hollow stated that he was Zangetsu; the inner Hollow stated he and Zangetsu were originally one being and the reader sees Zangetsu absorbing the Inner Hollow; Ichigo's Fullbring's initial form is the shape of his Bankai's hand guard and fires attacks in the same shape as the Quincy Cross, and while it was stated to draw on his Hollow power, its final form synchronizes with his Soul Reaper abilities. Even reveals that all Soul Reapers are given an Asauchi on which to imprint their Zanpakutou, with the exception of Zaraki and Tousen, who took the Asauchi of other Soul Reapers to use set up the reveal that Ichigo never having been given an Asauchi meant that his original "Zanpakutou" was driven by his Old Man inner spirit hiding the truth about his identity and Ichigo's power.
- There's also a clever bit of foreshadowing in the trailer for the anime adaptation of the Thousand-Year Blood War arc.
At one point, the phrase "Revert your roots" appears upside down and flips right side up, followed by a shot of Yhwach. It'd be easy to assume that this is just a bit of nostalgia about coming back to an old anime, but it's actually a reference to Ichigo's true Quincy heritage, and how it completely changes the context of several moments in the series. - Aizen makes a note early on in the final arc that the only reason Yhwach would approach him would be because he considers Aizen as much of a threat as Ichigo. Yhwach does not deny this and leaves Aizen sealed away. Yhwach is eventually beaten by Ichigo and Aizen working together.
