A young group of friends meet up for the first time in a very long time after finishing high-school. One of them remembers how once ago a girl left him Daisies and a love letter inside his locker, back in the high-school days. He has three suspects of who this secret lover could be and so there is only one way to know... by having sex with all of them.

What are some of the best anime series I should watch, in the mystery, tragedy, time travel, and maybe some romance genre?

Fullmetal Alchemist Brotherhood (64 episodes)-true masterpiece. Hunter x Hunter(148 episodes) Boku Dake GA inai machi(Erased)(12 episodes) Stein's Gate(26 episodes)- Excellent anime series showing time travel. Fate 0,Fate stay night unlimited blade warriors Attack On Titan(1st season 25 and 2nd season 12 episodes)-a must watch and very engaging. Death note(37 episodes)-Most popular anime in the world with most intelligent writing. Mushishi(26 episodes) and Mushishi zoku shou(2 seasons with 10 episodes each).
It is not for everyone.Quite slow but breathtaking Re Zero(26 episodes) Great Teacher Onizuka(48 episodes) Monster(74 episodes)- A very intelligent anime from a legendary director “Ursawa”. Sports anime like Hajime no ippo(The Fighting),haikyuu(3 seasons),one outs,Ping pong the animation are also good. Madoka Magica(11 episodes) Boku no hero academia(2 seasons 13 episodes each) Rainbow(26 episodes)- A very dark and engaging anime. One punch man(12 episodes)- It is the most popular anime of recent time. Classic Animes include Cowboy Bebop,Rahxephon,Trigun,Ghost In the shell, Samurai Champloo,Neon Genesis Evangelion,Samurai X(Ova 4 episodes),Dragon Ball Z. Ergo Proxy,Serial Experiment's Lain, Paranoia Agent,Mawaru Penguindrum are anime series which are very good but controversial due their non linear storytelling. Hellsing Ultimate(Ova 10 episodes)- Very dark and much much better the main series. Anohana(11 episodes),Toradora(26 episodes),Barakamon(12 episodes),Usagi drop(11 episodes),Your lie in April(26 episodes),Angel Beats(13 episodes) and Nodame Cantabile are excellent animes with lot of emotional appeal. Good horror Animes include Higurashi(when the cry), Hyouka ,Elfen Lied, Another. Psycho pass(season 1 22 episodes) Code Geass(2 seasons 25 episodes each)- one of the most popular anime series. The Count Of Monte Cristo (26 episodes)-Best anime series adapted from a book with beautiful animation.One of the most underrated anime. Eden of the east(11 episodes) Tokyo Magnitude 8.0(11 episodes) I forgot 2 life changing anime Ghurren lagann and FLCL. Some criminally underrated Animes include Now and then here and there(13 episodes),Noein(26 episodes),Last exile( 26 episodes),Time of Eve( 6 episodes),Kurenai(11 episodes),Princess Tutu,Space Battleship Yamato 2199( 26 episodes). Future Diary,Nanatsu taizai,Tatami Galaxy,Kaiji are also very good. Parasite and Baccano are excellent and I forgot. From the recent time,I found Made in abyss(13 episodes) excellent too and even Land of Lustrous(12 episodes).