Start at Spy x Family, Vol. 1 and read straight through. Tatsuya Endo's series has the simplest reading order of any currently-running manga — no sub-series, no prequels, no branching — and volume 1 is unusually self-sufficient, establishing Twilight's mission, Anya's telepathy and Yor's day job in one book. The joke the whole series runs on is that each of the three knows exactly one of those facts.
What a new reader actually needs is to know what is not the manga. The anime reorders and pads several early arcs, so its episode sequence is not a reading guide. The light novels are a separate line written by a different author and are not required for anything. The ordered volume list is on the Spy x Family path.
Volumes 1 to 4: Operation Strix
Spy x Family, Vol. 1 and Spy x Family, Vol. 2 are one setup — the fake family is assembled and Eden Academy, with the Damian dynamic that becomes the series' most reliable engine, arrives in the second. Spy x Family, Vol. 3 brings in Yor's brother Yuri and the secret-police thread, which is the first sign that Endo intends a plot and not only a premise. Spy x Family, Vol. 4 adds Bond and settles the cast into its stable shape. This is roughly where the anime's chapter order diverges from the books; follow the volumes.
Volumes 5 to 8: the family becomes a family
Spy x Family, Vol. 5 introduces the Stella Star system, which gives Anya a concrete goal and the school material a structure, so episodic chapters start accumulating rather than resetting. Spy x Family, Vol. 6 introduces Fiona Frost and is the best single volume for watching Endo handle a large ensemble. Spy x Family, Vol. 7 and Spy x Family, Vol. 8 are the cruise arc and should be read together: it is Yor's longest sustained sequence, the point where her assassin life stops being a punchline, and the most conventionally thrilling stretch in the series so far. Splitting the two wastes the build.
Volumes 9 to 13: the wider war
Spy x Family, Vol. 9 deliberately resets the pressure with school comedy after the cruise, and Endo's pacing instinct is clearest there. Spy x Family, Vol. 10 pushes Ostania and Westalis politics to the foreground, so the Cold War frame stops being wallpaper. Spy x Family, Vol. 11 gives Anya's backstory and the origin of her telepathy their fullest treatment, and it is the one volume that changes how the first ten read. Spy X Family, Vol. 12 — catalogued with a capital X, same series — brings the school plot and the espionage plot into direct contact. Spy X Family, Vol. 13 is as far as our catalogue reaches.
Where it stops, and a note on editions
Spy x Family is still serialising, so volume 13 is a stopping point rather than an ending. That is worth knowing before volume 1: you are starting an unfinished story, and the espionage plot in particular has not resolved.
Two of our records are not English editions despite their English display titles. The volume 2 record carries a Japanese ISBN and the volume 5 record a French one, so check the listed language before ordering those two specifically. Volumes 1, 3, 4 and 6 through 13 resolve to English editions cleanly.
What the series actually is
Underneath the family sitcom is a competent Cold War thriller, and the two halves increasingly use each other rather than alternating. The violence is stylised and the tone is warm, but people are shot, tortured and killed on the page, and the setting is an authoritarian state with a working secret police. It reads younger than it is. More ongoing-series guides are on Discover.
