Bye Bye YESTERDAY

Bye Bye YESTERDAY (バイバイ) is the fourth and final opening theme of the Assassination Classroom TV anime series. The theme is performed by 3-nen E-gumi Utatan, a group consisting of voice actors Mai Fuchigami, Aya Suzaki, Nobuhiko Okamoto, Ryota Ohsaka, and Shintarō Asanuma.

CD

 * 1. Bye Bye YESTERDAY
 * 2. Gekkō
 * 3. Bye Bye YESTERDAY (Instrumental)
 * 4. Gekkō (Instrumental)

TV Size
Romaji= Tonikaku mou "chotto matte!" Sakebi mo munashiku kiete Boku wa tada tada semaru LIMIT Zenryoku obietetanda

Genjitsu to wa yousha nakute Toku ni jikan wa yabai ne Sore nashi ja nemurenai BLANKET Ubawareteku no ni niteru

Ta'ai mo nai imi no wakannai Koto de warattari nayandari Saigo no CHIME narihibikeba Tanoshii toki mo owaru

BYE BYE YESTERDAY Sanbyakurokujuugo nichi bun no manabi wo Kaban ni tsumekonde Itsumo mitai mata ashita teki ni BYE BYE YESTERDAY Sanbyakurokujuugo nichi bun no dekigoto Boku wo otona ni shita nara Namida nante misemo shinaide

BYE BYE YESTERDAY Sanbyakurokujuugo nichi bun no omoide Motto otona ni nattemo Sukoshi mo iroasenai sa Kanji= とにかくもう「ちょっと待って！」 叫びも虚しく消えて 僕はただただ迫るリミット 全力怯えてたんだ

現実とは容赦なくて 特に時間はヤバイね それナシじゃ眠れないブランケット 奪われてくのに似てる

他愛もない　意味のわかんない ことで笑ったり悩んだり 最後のチャイム　鳴り響けば 楽しい時間（とき）も修了（おわる）

バイバイYESTERDAY 365日分の学びを カバンに詰め込んで いつもみたいまたあした的に バイバイYESTERDAY 365日分の出来事 僕を大人にしたなら 涙なんて　見せもしないで

バイバイ YESTERDAY 365日分の思い出 もっと大人になっても 少しも色褪せないさ English= "Wait, just hang on a sec!" I scream, but it gets me nowhere I put all my strength into being afraid of The limits that just kept on closing in

Reality is merciless And time is especially tricky It's like someone's snatching away the blanket I just can't sleep without

We laughed and fretted Over silly things, nonsensical things Once the final bell rings out The fun times will be over, too

Bye-bye, yesterday 365 days' worth of lessons shoved into bags Like always, like it's "see you tomorrow." Bye-bye, yesterday 365 days' worth of happenings If you've made me an adult, don't be showing me tears Bye-bye, yesterday 365 days' worth of memories Even if I grow up some more They still won't fade a bit

Full Version
Romaji= Tonikaku mou "chotto matte!" Sakebi mo munashiku kiete Boku wa tada tada semaru LIMIT Zenryoku obietetanda

Genjitsu to wa yousha nakute Toku ni jikan wa yabai ne Sore nashi ja nemurenai BLANKET Ubawareteku no ni niteru

Ta'ai mo nai imi no wakannai Koto de warattari nayandari Saigo no CHIME narihibikeba Tanoshii toki mo owaru

BYE BYE YESTERDAY Sanbyakurokujuugo nichi bun no manabi wo Kaban ni tsumekonde Itsumo mitai mata ashita teki ni BYE BYE YESTERDAY Sanbyakurokujuugo nichi bun no dekigoto Boku wo otona ni shita nara Namida nante mise mo shinaide

Nakattashi sentakushi Kitakute kitan ja nai shi Shiite iu nara gotsugou shugi ka na? Nagasareta chuukeichi

Kitai mo shitenai hazu no basho ni Yosougai SURPRISE PREMIA tsuite Ukkari hanaregatakute komarunda

Itsu no ma ni ka shimikondeita Boku no kokoro no sumizumi made Owatta tte sodacchau yo Ano kotoba ga michi ni natte

BYE BYE YESTERDAY Sanbyakurokujuugo nichi bun no omoi wa Kakaekirenai kara Koboresou sa koborete shimau ne BYE BYE YESTERDAY Sanbyakurokujuugo nichi bun no dekigoto Oitekeru wake nai kara Zenbu motte sorosoro ikou ka

BYE BYE Good Good time Susumou susumou susumou susumou BYE BYE School School life Kimi mo kimi mo kimi mo kimi mo BYE BYE Good Good time Susumou susumou susumou susumou Wasurenai School School life Itsumo itsumo itsumo itsumo

BYE BYE YESTERDAY Sanbyakurokujuugo nichi bun no manabi wo Kaban ni tsumekonde Itsumo mitai mata ashita teki ni BYE BYE YESTERDAY Sanbyakurokujuugo nichi bun no dekigoto Boku wo otona ni shita nara Namida nante mise mo shinaide

BYE BYE YESTERDAY Sanbyakurokujuugo nichi bun no omoi wa Oitekeru wake nai kara Zenbu motte sorosoro ikou ka BYE BYE YESTERDAY Sanbyakurokujuugo nichi bun no omoide Motto otona ni nattemo Sukoshi mo iroasenai sa Kanji= とにかくもう「ちょっと待って！」 叫びも虚しく消えて 僕はただただ迫るリミット 全力怯えてたんだ

現実とは容赦なくて 特に時間はヤバイね それナシじゃ眠れないブランケット 奪われてくのに似てる

他愛もない　意味のわかんない ことで笑ったり悩んだり 最後のチャイム　鳴り響けば 楽しい時間（とき）も修了（おわる）

バイバイYESTERDAY 365日分の学びを カバンに詰め込んで いつもみたいまたあした的に バイバイYESTERDAY 365日分の出来事 僕を大人にしたなら 涙なんて　見せもしないで

なかったし選択肢 来たくて来たんじゃないし 強いて言うならご都合主義かな？ 流された中継地

期待もしてないはずの場所に 予想外サプライズ　プレミアついて うっかり離れ難くて　困るんだ

いつの間にか　染み込んでいた 僕の心の隅々まで 終わったって　育っちゃうよ あのコトバが　道になって

バイバイYESTERDAY 365日分の想いは 抱えきれないから こぼれそうさ　こぼれてしまうね バイバイYESTERDAY 365日分の出来事 置いてけるわけないから ぜんぶ持って　そろそろ行こうか

バイバイ　Good Good time 進もう　進もう　進もう　進もう バイバイ　School School life 君も 君も　君も　君も バイバイ　Good Good time 進もう　進もう　進もう　進もう 忘れない　School School life いつも　いつも　いつも　いつも

バイバイYESTERDAY 365日分の学びを カバンに詰め込んで いつもみたいまたあした的に バイバイYESTERDAY 365日分の出来事 僕を大人にしたなら 涙なんて　見せもしないで

バイバイYESTERDAY 365日分の想いは 置いてけるわけないから ぜんぶ持って　そろそろ行こうか バイバイYESTERDAY 365日分の思い出 もっと大人になっても 少しも色褪せないさ English= "Wait, just hang on a sec!" I scream, but it gets me nowhere I put all my strength into being afraid of The limits that just kept on closing in

Reality is merciless And time is especially tricky It's like someone's snatching away the blanket I just can't sleep without

We laughed and fretted Over silly things, nonsensical things Once the final bell rings out The fun times will be over, too

Bye-bye, yesterday 365 days' worth of lessons shoved into bags Like always, like it's "see you tomorrow." Bye-bye, yesterday 365 days' worth of happenings If you've made me an adult, don't be showing me tears

The option wasn’t even open to me – It’s not like I came because I wanted to. If I had to give a reason, it’s ’cause I’m opportunistic; I went with the flow and found a good place to stop.

In a place I didn’t think I had any expectations for, There were unexpected surprises, with premium service – Before I knew it, it became hard to step away… what a pain!

Out of nowhere, it was soaking into me, To the very corners of my heart. Now, even if this all ends, it will keep growing; Those words have become a path forward!

Bye Bye Yesterday: 365 days of feelings, Are just too much to handle; It seems they’ll overflow – yeah, they’re gonna spill on out! Bye Bye Yesterday: 365 days of lessons learned, Can’t simply be left behind, So let’s just carry them all and get going already!

Bye Bye Bye, Good – Good time; Let’s move on, move on, move on, move on! Bye Bye Bye, School – School life; And goodbye to you too, you too, you too, you too! Bye Bye Bye, Good – Good time; Let’s move on, move on, move on, move on! A unforgettable, School – School life; Forever, ever, ever, ever more!

Bye Bye Yesterday: Stuffing 365 days, Worth of education in our bags- As we always do… as if saying, “See you tomorrow”! Bye Bye Yesterday: If 365 days of lessons learned, Have made me into an adult, I won’t even bother to show my tears.

Bye Bye Yesterday: 365 days of emotions, Can’t simply be left behind, So let’s just carry them all and get going already! Bye Bye Yesterday: 365 days of memories – Even if I keep growing up, Their colors won’t fade in the slightest!

Opening Animation
The opening features the classroom board which features various scenes of the anime, circles are used for the next scene in where as Nagisa, Kaede, and Karma are feeling happy and it switches to them being sad, same goes for the other characters when the circles switches, the next shows Korosensei in a deserted place touching the window with Aguri in a lit place then it switches to Korosensei in his human form and with the deserted place, Korosensei is watching the students play then switches to him watching no one, next it features the old campus and the E class sign next the E Class are in the classroom which Koro sensei is in front of them and switching to where he is gone, then it features the multiple scenes of Korosensei and the class, Nagisa is then running then Kaede then Karma, the side of the board the features the dates and faintly Koro sensei's face, then using the circles again, it shows the Reaper and Korosensei facing each other, Hiromi hugging Nagisa, Irina and Karasuma with their backs turned, as well as Gakushuu and Gakuho, then it switches with the young Reaper looking up to Korosensei whos back is turned in his human form, Irina and Karasuma are facing each other, as well as Gakushuu and Gakuho, and Hiromi and Nagisa then various scenes of the anime are shown in the blackboard again dissappearing with a writing depending on the episode, numbers are shown to be increasing in the background while there is a picture of Korosensei and the class, it ends with Nagisa turning his back to see an illusion of Korosensei on the old campus as Nagisa smiles and it features the old campus without Korosensei

Trivia

 * The deadline for Koro-sensei shown on the classroom blackboard goes closer to the deadline time in every opening (First is 83 days, second is 64 days and so goes on depends on the Episode itself)
 * In the final episode, the blackboard shows the "Congratulations on graduating" chalk art from the ending of the previous episode