Fate/stay night: Heaven's Feel II. lost butterfly

'Fate/stay night: Heaven's Feel II. lost butterfly' is a Japanese anime film produced by ufotable and directed by Tomonori Sudō. It premiered in Japan on January 12, 2019. The story focuses on the Holy Grail War and explores the relationship between Shirou Emiya and Sakura Matou, two teenagers participating in this conflict. The story continues immediately from Fate/stay night: Heaven's Feel I. presage flower, following Shirou as he continues to participate in the Holy Grail War even after being eliminated as a master. It is the second film in the Fate/stay night: Heaven's Feel trilogy.

The film was a commercial success, earning ¥1.5 billion faster than its predecessor.

Plot
After the previous film's events, Saber is presumed dead, effectively disqualifying Shirou from the Holy Grail War. Regardless, Shirou intends to continue fighting and goes to Rin's house to discuss strategy. Upon returning home, Shirou finds Sakura has been kidnapped by Shinji and confronts him with Rin. Sakura pleads for everyone to stop and Rider heeds her call, revealing Sakura as her true Master. Shinji demands Sakura's final Command Spell to let him control Rider again, but she refuses. Shinji then resorts to using a potion that causes Sakura to lose control of her mana and accidentally injure Shirou before fleeing. Archer and Rin attack Sakura, but Rider defends her and removes her mask to reveal herself as Medusa. She starts turning the three to stone with her gaze, but Shirou is hurt further in saving Rin and Sakura's grief causes her to injure herself, forcing Rider to stop.

Shirou awakens in Fuyuki Church, where Kirei Kotomine operates on Sakura. He reveals her body is infested by Zōken's Crest Worms, which feed on her mana and cause her to feel extreme arousal. As Rin resolves to kill her for this, Kirei reveals she and Sakura are blood sisters and that Sakura was given to the Matō family for adoption. Despite Sakura's attempts to push him away for his own safety, Shirou promises he will protect her even at the cost of his ideals, which causes Rin to also give up on killing her. Sakura then moves back into the Emiya household and daily life soon returns to normal. Rider also moves in and slowly begins to trust Shirou. However, Sakura regularly gets aroused due to the Crest Worms and her behavior becomes erratic.

Shirou and Rin seek out Illyasviel von Einzbern to form an alliance, but find her in battle with Zōken and the shadow. The shadow unleashes Saber Alter - a corrupted version of Saber - who subdues Berserker so the shadow can devour him. While Archer is able to drive Zōken's Assassin off, the shadow mortally wounds him and severs Shirou's left arm. Before he dies though, Archer cuts off his own left arm and transplants it onto Shirou to save his life. Rider then arrives and takes everyone to safety. Afterwards, Rin and Illya move into the Emiya household to plan their next move since they have lost their Servants. The two also help Shirou get used to his new arm, which must remain sealed using a cloth as his body cannot handle Archer's power within it. However, as Rin grows closer to Shirou, Sakura becomes jealous and asks him if he really loves her romantically, to which Shirou affirms that he does and the two have sex.

One night, Sakura sleepwalks throughout the city and kills several people. The Servant Gilgamesh attacks her, but the shadow devours him. Sakura then returns to the Emiya household and Shirou realizes the shadow comes from her. Due to injuries she sustained from Gilgamesh, Sakura is bedridden and Illya tells her that she has become the vessel for the Holy Grail, thus she does not have long to live. Illya, who is secretly Kiritsugu Emiya's biological daughter, also lets go of her grudge against him, after Taiga reveals he tried to rescue her from her abusive family rather than abandoning her. Shirou is later approached by Zōken, who reveals the shadow is a piece of the Holy Grail from the previous Holy Grail War he put inside Sakura and that it is not his ally at all - in fact he can barely keep it contained. Zōken tells Shirou the only way to stop the shadow is for him to kill Sakura, as he is the only one she trusts enough to let close, but he cannot bring himself to do it.

Seeing herself as a burden to Shirou, Sakura orders Rider to protect him with her last Command Spell and returns to the Matō estate, with Shirou giving chase. Once Sakura arrives, Shinji attempts to rape her, blaming her for his inability to become a magus. Threatened with Shirou discovering Shinji has raped her for years, Sakura panics and kills her adoptive brother in retaliation. As she realizes what she has done, the shadow appears and fuses with Sakura, corrupting her.

Production
The film was revealed for the first time in May 2018. Director Tomonori Sudō found it as challenging film to develop but expressed joy in how fans reacted to the movie. Sudō further stated that he aimed with the film to take a larger development in Shirou and Sakura's characterization due to certain scenes. Another staff member stated the film has an impactful ending and looked forward to the release of the third and final Heaven's Feel film to follow the story's cliffhanger.

The Japanese cast remains unchanged with Noriaki Sugiyama expressing how Shirou was given a different take on his character, aiming to give him a cool-headeadness style. Noriko Shitaya enjoyed Sakura's feelings being noticed by Shirou in regards to her being in love with him. Ayako Kawasumi had mixed feelings about Saber's darker characterization in the form of her new form, Saber Alter, but still wanted the fans to see her character in action.

On November 1, 2018, it was announced that the theme song for the film "I beg you" was composed by Yuki Kajiura and performed by Aimer. "I beg you" was written to explore the relationship between these characters as Aimer wants to show Sakura's dark personality as she aims to be loved by Shirou but does not want him to know about her secrets.

The film was released in Japan on January 12, 2019. Aniplex of America announced at Anime Expo 2018 that they would release the film theatrically in the United States, with a premiere at the Regal LA Live in Los Angeles on February 23, 2019, and a wider release, in collaboration with Fathom Events, screening theatrically from March 14, 2019. It also opened in Canada on March 14. In Australia and New Zealand, Madman Entertainment announced that they would premiere the film at Madman Anime Festival Sydney 2019 on March 16, 2019, with a wider release scheduled for later in the year. It will also opens in Malaysia on April 18.

In promoting the movie, the developers made a collaboration with Pizza Hut in Japan. In promoting the movie, various characters from the feature were added to the game Puzzle & Dragons.

Box office
The film debuted at the top of Japan's box office selling 363,080 tickets to earn ¥602,841,741 (US$5.55 million) in three days. The film sold 12% more tickets and earned 18% more in its opening weekend than the first film in the trilogy. By its 12th day, the film surpassed ¥1 billion, once again surpassing the record of Pressage Flower. The film dropped to number four in its third week, and to number ten in its fourth week, earning a total of ¥1,320,295,396 (US$12 million). By its fifth week, the film dropped from the top ten, still earning 57,369,900 yen (about US$518,900), for a total of ¥1,429,918,296 (about US$12,93 million). By February 19, 2019 it has sold over 1million tickets and grossed over ¥1.5 billion (US$13.54 million) in Japan.

Overseas, the film grossed HK$1.15 million (US$) in Hong Kong. The North American debut of the film earned $420,595 at the box office in March 2019. It also grossed $394,045 in South Korea, Australia, and Argentina, bringing the film's worldwide gross to US$.

Music
The theme song "I beg you" topped Oricon's charts with 31,000 copies sold.

Critical response
Anime News Network gave the film an "A" overall score praising its dark plot and relationships of the main character. However, the writer believed new viewers would not understand it. The Fandom Post gave it a "A-", praising the fight scenes between Saber Alter and Berserker as one of the main highlights for its execution in terms of animation. Like Anime News Network, the Fandom Post liked the development that Shirou and Sakura have but stated that viewers might feel uncomfortable about the latter's feelings in regards to the themes of sexual relationships. IGN felt that Sakura's personality was the one of the best parts of the second film due to how she suffers a darker characterization despite retaining her original wellmeaning self. The fights between Servants were also noted to be the biggest focus of the movie. SDPNoticias stated lost butterfly was superior to its predecessor to the point might be the franchise's best release so far. SDPNoticias praised the movie for it focus on the relationship between Shirou and Sakura as well as its multiple servant battles which were noted to be high appealing. However, the reviewer noted that fans of Illya, Gilgamesh among other characters would be disappointed because the narrative does not give them too much screentime to stand out. The use of nudity of and gore still felt fitting for this adaptation of the visual novel as it more important in the Heaven's Feel alongside its fight scenes while the visuals were also well-received with Sakura's protagonism being found more noticeable.